Don't get it?
What's not wanting to do leg training got to do with true muscle failure in other body parts?
I am confused by your post.
It indirectly tells me that you're not truly devoted to lift. In case you
are, you dive deep in EVERY muscle group. Your legs are roughly 50% of your body, so train them before someone calls
you a gym rat.
As for muscular failure, there's no need to go to failure each time. I believe it's counterproductive on the long run. Smart lifting means applying some kind of periodisation.