Actually there really are people out there on the internet that think spawn killing is somehow a legitimate way to "win" and you somehow deserve it if it happens. I personally thing no one deserves to play against people that spawn trap or kill in the first place. Maybe it's funny to do it like one time if you've never done it. Just drive all the tanks into the spawn zone and start going nuts just for a laugh. But everyone lining up to systematically frustrate the other team into quitting one by one is [censored].
People who have logic as you described above, are really quite biased in their views. If both teams were equal in skill, then perhaps the "you deserve it if it happens" argument would suffice, but the majority of situations are simply random players being grouped together, with varying skill levels amongst them - One team may have a a bunch of pros while the other team has a bunch of garbage players or it could simply be one team works better together than the other.
Whatever the reasoning is, spawn camping to me, just seems so juvenile - like it's a players way of "proving" his superiority over other players, since he can't prove it legitimately on the battlefield.
Even when I am dominating a team, I never move up to spawn camp, mainly because it;s just a dike thing to do, but also because the game is much more interesting when teams are actually playing the game and fighting each other.