I don't think they're doing it for you bro. They're doing it for themselves and trying to prove that they can still do something extraordinary despite their disabilities. You might say what's extraordinary about a high-jump or javelin throw because you or many of your friends might just be doing it everyday? Well, you might want to try it out with one leg tied behind your back to simulate an amputee and then perhaps you'd understand! Peace!
The Paralympics is pretty shit. No one actually cares about it, but many feel obliged to pretend they do. I'm certain 99% of disabled people couldn't give a fuck about it either.