I'd support Sum of Squares if it was implemented for games with a winner (so, a balance between current PPSC and WTA scoring), as long as draws are still everyone scores equally. Which I know is entirely counter to what people are intending for Sum of Squares, so instead it must be decried as absolutely disgusting - a draw is a fucking draw; survival to reach it is the *only* metric that is relevant in a game that did not have a winner.
tantrumizer does raise a good point, that Win/Draw/Survive/Loss ratios are already rendered almost meaningless with variable game sizes - even your entirely average 1v1 player is going to have their Win percentage trend towards 50% simply from competing in games where they have a 50% chance of actually winning. It thus follows that having PPSC as a option does not detract from the site as a whole, given the entirely available option to simply not use it if you dislike it, and the fact that it's presence has demonstrably less effect on anything that matters than the entire point of the site (hosting variant maps; ie. maps highly likely to have different player numbers than the default 7).
In the meantime, PPSC adds diplomatic layers for people who want them (as such, those people who are actually likely to play a PPSC game, and thus those actually affected by any change to their availability - ie. none of the people in this thread arguing that they're shit). If you're in a dominant position, they allow you to actually play for a win while still rewarding loyal allies, rather than be forced into playing for a draw so as not to shaft them (always a shit thing, both the screwing someone over after lengthy productive cooperation, and playing for a draw). They also encourage people actually playing to win, rather than needing to think about 'how can we force a draw in this' from the fucking get-go as you basically have to in any WTA game of sufficient size.
In conclusion: PPSC is not hurting you. If you don't like it, don't play it, and let those who /do/ like it enjoy themselves.