I think you guys are over thinking this. The fact is that real MA training is a lot of hard work. Most people these days are not into hard work. They're into instant gratification. A lot of people see MMA fights or kung fu movies on TV and think it's real cool until they take a couple of classes and realize how hard it is. Even young kids these days are in terrible physical shape. I'm 57 years old and I've seen a lot of teenagers that can't keep up with me because they spend their days sitting around watching TV and playing video games and their diets consist of nothing but carbs and empty calories. Then they get their moms to sign them up for karate lessons because they think it would be cool until they find out how hard it is. Then they drop out and go back to their electronic fantasy world. The reason there are so many McDojo's is because the McDojo makes it easy. You can pretend like you're a real martial artist and get a black belt without having to endure all the pain and suffering that goes with real MA training. There is no contract plan or marketing program that will finally overcome that problem. The best way to motivate a student IMHO is to know your stuff and refuse to compromise. Be a person of integrity and build a solid rapport with your students such that they will find motivation in not wanting to disappoint their sensei.
You know I agree with you but..... I think you are way over simplifying things when you say it is because the youth of today are just sitting around playing video games, they come in expecting to be Bruce Lee or (the current MMA star) in a few weeks and when the realize the hard work they drop out. I mean yeah some of my students have a work ethic that needs improvement and that is one reason they are in my class, not the only reason, but just one of them.
But for the majority of my students they have a good work ethic and need to be trained in strengthening that work ethic, but their time is limited and they are over scheduled. For instance I have 2 young kids 10 or 11yrs old; they go to swim lessons then they come to my class, today they came from the pool to my class (they might have come from a meet where they took 3 firsts and 2-3 seconds (they are twins competing in the same events). I have students who are in marching band out in the TX sun come to class dog tired from the heat, kids that are in AP classes doing homework prior to class and then after class. I have kids doing boy scouts, girl scouts, baseball, soccer, basketball, like I said swimming, band, music lessons, family vacations, tutoring etc. etc. in addition to my classes. I'm sorry these kids aren't lazy.
Now here are some of the real reasons they quit,
1) They lose interest. Some students just don't want to keep doing it after a certain belt rank.
2) The parents have over scheduled the kids and they get burned out.
3) School related functions, i.e. Band, Sports etc. etc. I lost my two Red belts due to marching band, possibly losing another Red belt in the fall, they couldn't commit to training for black rank and keep up their school related functions.
4) Parents pulling the kids out to "try" another sport. "Hey it's baseball season and we want to try out little Billy this season." Take the child out of class and let all of his friends/classmates pass him by and see if he comes back. My two swimmers, Dad pulled them out for August and that turned till January, this year the kids have told dad we don't want to miss our test so they are coming to class after swimming.
5) They relocate due to parents moving.
So while I know that some kids don't want to go through the hard work it takes to get to their black belt and beyond. In my experience most of the kids that quit at my school quit for different reasons some of which I mentioned for examples. If the truth be known the ones we think or blame for being "lazy" quit because; we as instructors or what we teach didn't meet their needs or expectations.