Nexus Blitz - Sometimes Surrender IS the Option
I used to be a hardcore advocate of the idea of "Never Surrender." I still AM a hardcore advocate of Never Surrender in Summoner's Rift. Yeah, the snowball can be kinda sucky, but come on you -might- actually win.
However the snowball in Nexus Blitz can be quite intense. You should take a look at the Gold Gain graphs for these matches. Sometimes, when your team is somehow magically down by 16 kills by the first event, and four of you dive on a Lux and can't take her down without all dying? Surrendering is now the option.
Don't just sit in the game, banging your head on the wall, getting upset at the one person who just wants out of there.
Edit: Since there is some confusion about the first paragraph... if it is blatantly obvious we are going to lose, even in Summoner's Rift... I will surrender. I mean that half the population try to surrender after first blood, or when they fail a combo and the enemy gets a double kill.