What characters do you think are clients of Quinn's restaurant? I suppose that Quinn didn't propose the deal to Derek because he's Maya's brother, but, what about the other DIKs? As far as we know, at least Tommy, Rusty and Jamie have been with Riona, don't remember if some other guy too, and chances are, not for free... Do you think Derek is the only DIK that doesn't know about it?
Anyway, I think that to make the HOTs whores doesn't make any sense. They can't maintain the business only with the DIKs as clients. IRL, the clients of that kind of things are not students, that usually don't have a lot of money and fuck for free anyway, except if they are really ugly or shy. Clients are old, rich people outside the campus. And it's impossible to maintain the secret if they are fucking with students around the campus and giving blowjobs in toilets. Clients would talk. Even if it's a gloryhole, for sure it wouldn't be difficult to find out who was the girl doing the job.
And over all... Why MC doesn't even mention it for 9 episodes, if he didn't accept the deal with Quinn? He just pretends that he don't know that Quinn, Riona and Camila are whores... He doesn't even think in telling something to Sage if he's in her path, knowing that she's going to be harmed if the scandal of the prostitution ring into the HOTs breaks... Those are huge plot holes IMHO.