Our boss agrees that we shouldn't be doing this but he doesn't want to have to fight with people constantly so he just lets it slide and tells me to tell the other developers to push back. 80% of code is now going out without
He's asking you to do his job. Thoroughly unprofessional. This should not be a constant fight. This should be an absolute law and the fighting would stop after a written reprimand or two.
There's really not much you can do in this situation. You and the other developers that care could try peer pressure, but it doesn't seem like there's enough that care enough, or haven't (understandably) given up, to make a difference.
I'd honestly start looking for another job
EDIT:
Another option, if you feel like you've tried everything with your boss, would be to go over your bosses head to their boss and seek to address this further up the chain. This would need to be done carefully, and possibly anonymously, as going over your bosses head can have serious repercussions.