The personal training industry. Ever since the popularity of the biggest loser, it's now the biggest push to become a personal trainer, where you see celebrity trainers endorsing corporations that make you a qualified personal trainer for 'X' amount of money. What they don't tell you though is the turnover rate, of the people who finish the course how many get a job and keep it. Of my course of 30 people, there were probably only 8 who got a job, of that only about 5 are still training. Given that some of the people who did the course was for their own benefit though, but not 22 of them. I've seen many trainers leave my gym since I've been there, I became the lead trainer there within 6 months. With a flooded market of PT's trying to get a job, they'll do anything to get in clients, willing to charge low prices to get people in the door, where if they fuck up and injure a client, that client will be turned off exercise for life and probably resort to an unhealthy lifestyle, giving all personal trainers a bad name. That's another thing as well, experience and what they teach you in the course. Here's a hint, it starts with 'F' and rhymes with 'Tuck Balls'. Give up? It's Fuck alls. They basically give you a little taste of everything and you have to go out to do specific courses to get further accreditation, which isn't a bad idea as it forces us to constantly learn and weeds out all the bad trainers, but when trainers come straight out of a course thinking they're qualified boxing instructors than that's a different story. I'm from Australia so I don't know how if it's done differently over seas, but I know with the franchised gyms such as Snap and Anytime Fitness, they will charge trainers $250 rent a week, regardless of if they have clients or not. I was lucky to get a gym that doesn't do this, but if I did I would probably not be training to this day, it's slow and hard to get clients in my town with everyone being cheap and lazy, (Not exaggerating, we have been rated high for our laziness).
Final point, when everyone is a personal trainer, no one is.