Nope. I look at it like religion. Look at the likes of Creflo Dollar, Joel Olsteen, TD Jakes, the late Eddie Long, etc.
What do they have in common? They're either non-denominational or belong to Christian denominations with a congregational polity. In other words, their churches do not belong to larger organizations where bishops or elders can hold individual pastors accountable.
Back in the 80's, when Jimmy Swaggart got caught in his scandal, he was immediately dealt with by the World Assemblies of God Fellowship (which has a presbyterian polity).
Who's going to hold Creflo Dollar or Joel Olsteen accountable? No one.
With a large organization that teaches martial arts it can be hard to keep an eye on everything. The president of such an organization might be a really good instructor and if you're learning directly under him you might be getting top quality instruction but when there's many many little schools that all function as part of said organization some of those schools might only offer sub standard instruction and it can be hard for the president to supervise each and every school all the time so bad instruction can crop in. Im not saying this will always happen with every school in a large organization but it is something to look out for if you want to train in such an organization.
Is this to say that martial arts instructors will immediately take their schools in bad directions if they're independent? No. But there's also no one to stop them if they choose to do so.
Yes that is true you can find bad instruction in independent dojos too, that's why I will always watch at least part of a class before I sign up for lessons at a dojo, or if Im allowed a free trial lesson as some dojos offer I will do that before committing to regular lessons. That's what happened when I wanted to learn Goju Ryu, the first dojo that I visited that taught that art, after watching part of a class I was not impressed with what I saw so I went to a different dojo that taught Goju Ryu, that was further away from me but I liked the instruction better so I signed up there instead.
How do you assess the quality of the material being taught?
Mostly by trusting in my own judgement and my decades of experience in the martial arts. Sometimes, also by talking to other people in the martial arts community speaking of which I was not the only one who wasn't impressed by Tiger Schulmann's. Speaking of which, you used to be able to find Tiger Schulmann's in many if not most strip malls, now you hardly find it anywhere.
If you're qualified to judge that, then why don't you have your own dojo?
Because starting a dojo requires collateral.
If that's the only way to get it, sure. But if there are other ways, I'd rather try them first and risk embarrassment as a last resort.
Let's say there's this job you want, the only way you can possibly get the job is to apply. If you do apply you might be turned down which can be embarrassing but you certainly won't get the job if you don't even apply in the first place.
As for only asking an instructor directly about how the dojo is run, including belt requirements, only as a last resort, if such information is not posted on the website or anything, that's your choice.
Yes. You yourself have given numerous examples of this happening. I've never asked an instructor this question before, so I can't speak from experience. However, I'm taking your word for it. I'm also taking the word of posters here who've discussed the times that they themselves answered this question.
If you're talking about when I mention about an instructor offering to sell somebody a black belt right out of the cabinet that they haven't earned with skill, as its been mentioned in this thread before, yes that would be treating somebody like a child but it can be turned around. For instance if an instructor did that with me I would say that's cheating so I would be pointing out that he suggested that I cheat.