I haven't been, but some good dance-friends of mine are stuck at a studio who's robbing them blind, and they don't even realize it.

This is the same "put your students in an uncontested heat" studio, and also one who recruits newbs to be teachers/six-week wonders, and they have some very "chain-studio" policies for an indie. No frat, no compete agreements, things like that, their students act whipped and scared to associate with us in any other medium but their own home turf, we've been "politely disinvited" to their parties because they're scared their students might look up and see something they haven't learned yet, etc.

We feel bad for them, but if they like that flavor of Kool-Aid... meh, more room for us.

Be very careful when dealing with studio instructors/managers. Yes, it is a business and it's not so much about you but the amount of "units" or dance packages they can sell you. I've seen every approach, some quite innocuous, some rather nasty. It depends on the individual(s). This may come from your teacher during a debrief session or you could get "tag teamed" using pressure tactics to sign a stiff contract designed by your instructor with a package they think is in your best interest. This could consist of 30 units or more with a large price tag attached. Read the terms and conditions carefully, do not sign anything until you are comfortable with the terms. If they persist, walk out. Not all schools are like this.

Anybody, or group can if they wish publish a list of professionals who are qualified to teach having passed an examination with a reputable society
If the controlling body wont then why don't we.