Remember, Johnny came from a terrible household. His parents either beat him, or ignored him. If Johnny became crippled, he wouldn't be able to come and go from that house as he pleased, which means he has to stay in that home where he was hated and unwanted.
Here is the excerpt from the novel:
"Even if Johnny did live he'd
be crippled and never play football or help us out in a rumble again. He'd have to stay in
that house he hated, where he wasn't wanted, and things could never be like they used to
be. I didn't trust myself to speak. If I said one word, the hard knot in my throat would
swell and I'd be crying in spite of myself." (Hinton, 87).
