For the most part, this is a true statement. We can all agree (I think) that when we gripe about the things we see in TMA, MMA or really anything else, they often have to do with commercialization and ways to monetize a hobby. Making money often comes at a cost (no pun intended).
TKD... there are some great schools out there, I hear. I personally don't see those. Granted, I'm not looking, so I'm going to take you guys at your word. But the TKD schools I see are the ones full of kids in the strip mall down the street.
There are notable exceptions. Not every school is run for profit. We hear about schools that are run as clubs or non-profits all the time in the USA. It is actually very rare to find a Judo school in the USA that is run for profit. That doesn't mean their free. It means, though, that they can dispense with marketability and focus on the art.
All of that said, your point is a good one. Unless you're running a school as a non-profit, a charity, a club or just flat out teaching for free, you're tossing stones in a glass house. Any criticism of MMA for effective marketing just doesn't resonate. Even within the MMA community, there are folks who like to think of themselves as purists. Like it or not, the UFC is putting money in everyone's pockets. If you aren't riding the MMA tide, you're marketing yourself against it. It's generated a lot of interest in martial arts in general, and is giving a lot of martial artists an opportunity to make a living doing what they enjoy.