Football is also the only sport where practice seldom includes playing the game. Yes, all sports require practicing certain skills, but for the most part, you practice basketball by doing the things you do in games. Ditto for baseball, hockey, golf, tennis, etc. Generally speaking, practice is fun in most sports. Football practice is about repeating drill after drill after drill after drill.
Pitchers study hitters and vice versa.
Golfers study tapes of their swings. But no athlete spends more time in the classroom studying tape and going over assignments than football players. Also, football requires certain physical attributes. If you're not very fast or very large, the game isn't for you, and these days you'd better be fast AND large if you want to excel. Sure, being tall helps in basketball, but there is a place for average-size people.