It might have to do with, most Asians have really shiny, pretty straight hair no matter what they do. My hair goes wavy when it’s wet and fly away and I like my hair straight or at least not frizzy lol. Flat ironing is a pain. So I won’t get my hair wet. Plus I don’t buy water proof makeup as I like it to come off easy when I do my night routine. If you’re at a parlor, it can get pretty busy sometimes so your makeup and hair has to stay good. I’ve worked in a few spa like settings and the showers in room are usually single person stand up. There’s not room for 2.
We replace the shower head with a hose, so the ladies don't get their hair wet. It's really a non-issue. Anywhere that does shared shower does the same.
Honestly, it's done for a few reasons..
A) Some guys just don't really clean themselves well... And can go as far as to run the water and not get in if left to their own devices (I think they feel if they get it done faster then they get more play time?). For this reason, shared shower lowers the risk/occurrence of UTI.
B) Clients want to see that the girl is clean as well.
C) To control the pace of the session. There is always going to be that one guy who takes a 30min shower after the session and goes well beyond his scheduled time.
D) Clients generally like it, and it's been a thing for so long it's to be expected.
So those are the practical reasons. I wouldn't exactly lump us in with the foreign run places, but we do really agree with the above and follow that.
SPAs don't do the shared shower thing because it lowers the overall efficiency for them. A girl can hop straight from one room to another (one guy is getting ready while another is finishing.. ie the fast food concept lol) where in the condo setting the girls have to reset/use the same room... And yes space is often at a premium so many solo size stalls.