Backing up a bit...yes there are many well-off Thais who come to HH but I don't think they are a market.
1) They have a maid to do it in BKK. Nice clean clothes and fresh bedding when they come back Sunday night.
2) They have a Thai-speaking laundry in or very near their condo, often at the ground floor.
2) How would you reach that market anyway?
4) Why would they give their business to falang? For many Thais business is about extracting money from falang not the other way round.
5) Thais will choose the cheaper one. Look at internet cafes - a race to the price bottom.
6) Hotel business will be a high-volume low margin affair. Sailing a bit close to the wind I think.
Not being negative, just trying to be realistic.