Neither do I understand the whole upgrade 'argument'. It's like detractors believe that PC gamers run 3D Mark every 28 days on a new batch of part-exchanged GFX cards just to make sure they're pulling bigger polys than their friends. Last time I upgraded (late 2008), I only did so because my (2003) Radeon 9800 Pro had started drawing garbage all over the screen. It had only just started falling off minimum spec sheets, and was giving me a far better Orange Box experience than the PS3 managed at any rate.
However: when it comes down to these hardware arguments, it can be no surprise that my console manufacturer of choice is definitely Nintendo. They make games I actually want to buy a different machine to play. Oh, and since I live in a house with all three home consoles, It's not like I have to choose.
edit: Oh, the PC / Console rift is irrelevant anyway. Valve may have embraced them, but the contempt PC gamers have for Mac users ('Mac gamer' would redline the spell-checker) burns like a million stars being fired into a supernova.