Soccer or basketball players can't deal with the physicality football players do. Toughness is the barrier of entry for football, in place of skill.
You probably know that though, so I'll just let you get back to trolling now.
@ Toughness, basketball players have a good union, they don't have to worry about being cut if they get injured. They don't have to go back out there with a concussion and blood leaking out their ears....because they have actual guaranteed contracts.