^^
From my own humble experience, a band where everybody has to fully approve new songs is rewarded with a very slow-growing and unresponsive repertoire. Been there, done that. It's not ideal in practice, though it sounds good in theory.
It wasn't too bad for us but we were pulling from a pool of largely 70's-90's rock which had less chance for stuff to be really offensive to any of our sensibilities.
I think the bigger problem was when we'd have one member gung-ho about a song and everyone else was indifferent so we'd give it a shot and many times it wouldn't go over well. So we would can it and basically our time was wasted.
I remember one of my bands spent a lot of time on Foreigner's "Cold As Ice" because our singer was just adamant it would go over awesome. So we learned it to a tee. Five of the six guys sang so we worked out a lot of the intricate vocal parts at the end and got it sounding great. Take it to the stage - crickets. It's one of those songs everyone gets excited when they hear the beginning, but they already don't give a **** at the one minute mark. So we just kept playing "Feels Like the First Time" to satisfy any Foreigner requirement, which is a lot more boring to play for me, but always went over.