I'm tired of seeing allies in ranked go 0/3 in lane, calling 'GG', and giving up for the rest of the game and playing shitty because they already think it's over at 5 min in. Then when they lose the surrender vote 1/4 they say 'wtf team just end' and intent feed for the rest of the game.
If you don't let them surrender in ranked then they might actually try to play the game out. You should never surrender at ranked. Even if you only have a .001% chance at winning I don't care because that's a better chance of coming back than the 0% of surrender.