I hope I can shed a little light here, as an ex-Somtawin teacher (I had an account on here but can't remember what the password was I've not used it in ages). I'm presently in the UK working on getting myself fully qualified to be a better teacher, having learned a great deal in my time at Somtawin, and hopefully helped my students learn too.
If I may, I'd like to just offer my own opinions on this, which are solely my own and do not reflect the position of anyone else other than myself! In other words, I'm not representing anyone but me. I'm not here to pick any fights, so please don't interpret it as such, rather here to inform and perhaps offer some insight into what's going on.
The first thing is that education in Thailand is, on the whole, not very good. Having seen what goes on in Thai schools there's no way I'd send my kids to one. I'd also say that it's far from perfect in the UK (I've just been invigilating mock GCSE exams and the papers were an embarassment, STW 4th graders could pass the foundation maths).
If you are in Thailand and have kids, sending them to a state school will do nothing for them. They'll be in a class of 50 learning by rote. If they're farang they'll have a real problem because if they leave Thailand they're stuffed. If they're Thai then you're denying them the opportunities they deserve, as their richer colleagues at nicer schools WILL learn more and earn more.
This means that the only options left are private schools. This is not ideal. I know it, you know it. The frustrations of education as a business drove me fairly mental on many occasions. However, Thailand is a weak state with a fairly poor government lacking sufficient tax-raising powers to develop a proper education system, along with various other infrastructural failings which I'm sure we're all aware of but should leave for another post.
To be perfectly blunt, Somtawin ran at a loss for all the time I was there (3 years). It never made a profit. Not a penny. The owners subsidised it heavily in the hope that one day it would be able to make a profit, I think with the long-term idea of Bangkokians sending their kids boarding to Hua Hin. Continuing on that trajectory there will at some point be no school. In that regard, the school making a loss is a problem for EVERY parent at Somtawin.
Regarding that loss, a fair amount of the problem is due to parents not paying fees. A few times staff weren't paid, and then the money had to come from the pockets of the investors directly, so as to keep things going. Another reason is that STW has an unusual number of foreign teachers (I remember when I mentioned the numbers at a job interview for a school in Bangkok, which I turned down, the interviewer just sat there stunned for a minute or two). This does improve the quality of education you get, as it's hard to find Thai teachers who don't teach by rote, simply because that's all state education does. It also costs a lot, farangs are expensive. The compromise made here is to have better quality teaching staff, by cutting costs with resources, though the person who simplified it to 5 kids paying the salary of 1 teacher has it wrong, one must remember many other things which are needed, such as classroom resources, the building itself, admin, and even just the simple fact that 1 teacher teaching all the classes would quickly burn out, so you need more than that anyway. Break-even point is a lot more than 5 teachers, though I'm not sure the bosses would appreciate me giving out the numbers, so I'll keep that under wraps unless advised otherwise.
Anyway, back to non-fee-paying parents. In short, students being present at the school cost time and money. That is recouped through fees. We have a certain standard cost per grade of course, but one should also remember that some of the costs are variable, in terms of resourcing for lessons, admin, teacher time, etc. If a large chunk of any given class is not paying, that class is running at a loss. Do the maths, too many losses means no school, everyone loses. Additionally, if parents see other parents getting away with not paying don't you think they'll decide not to bother paying too? To an extent, I think this may be STW making a statement to reduce the numbers of people choosing not to pay. They have to do SOMETHING about it, otherwise the school won't exist, which hurts everyone (including those at other local schools due to reduced competition).
That said, judging from what I've seen on here, this has perhaps not been handled perfectly. What we don't know of course is what private conversations the school has had with parents, though I know from experience that some parents just choose to ignore any contact from the school that they find inconvenient so to a degree the school's caught between a rock and a hard place.
Regarding the people suggesting that people should go home if they don't like it, I'd make a qualified agreement with that. For some people, Thailand is the wrong place to bring their kids. One example is the complete lack of provision for students with special needs. We did our best at STW but we weren't equipped or trained to deal with students with SEN, when I compare against what I see here in the UK (where trained Teaching Assistants work with SEN students, providing care and assistance that is just impossible in Thailand). Part of this is of course due to the Thai concept of 'face' and parents not being willing to admit their child has special needs, and part due to lack of knowledge and resources on managing those issues. If your child has special needs that require that level of support you should think seriously about your choice to live in Thailand. This is about responsible parenting, and if you're farang, you've made a conscious decision to come here, and chosen paid education here over the free options back home. It also means that you should have contingency plans in place should you need them. If you think you might not be able to afford to give your children a good future then perhaps you should not come to Thailand until after they have grown up.
Unfortunately I think some parents couldn't go back home due either to financial commitment to being in Thailand, or a desire to hang onto the lifestyle (and it's a hard thing to give up, as I've found out).
Part of my decision to leave Thailand (at least for now) was an increasing realisation that I could not have children in Thailand. I could not afford to give them an education at an equivalent standard to the UK (I should note that I regard STW as being ahead on Maths and Science, behind on some other subjects). Were STW to not exist my options would be even bleaker, with most of the other schools locally not providing enough of their education in English (sorry, the world speaks English and that's what I want my kids to speak) or simply not offering any kind of quality. My other options would be Bangkok prices, which are beyond me. I realised that I cannot bring a family up in Thailand, and made a responsible decision to return to the UK, to increase my earning potential and because it is only here I can provide for my kids properly. Other parents may need to decide what sacrifices they wish to make for their children, that's their choice.
Ultimately having a child is a huge responsibility, and something that requires hard work and sacrifice, and if it means sacrificing the dream of sitting on the beach with a warm beer til they've finished uni then that's the sacrifice we all have to make. See you all in 30 years!