You have to take into account some other factors too.
1. Xbox 360's have lower latency controllers and higher framerates in most comparable games (I.E. multiplatforms). So even if the network experience is identical people will still feel that the Xbox Live connection is 'better'. Also the other most compared game, Halo 3 had 100ms latency vs 188 IIRC for the PS3 Killzone 2.
2. The Xbox 360 has skill ranking/comparison in play in all games so you're more likely to be put in with people at your skill level and therefore have a fun game instead of getting your arse handed to you.
3. The Xbox 360 OS makes it easier to play with friends and keep playing with them by setting up parties etc.
4. PSN wasn't really considered 'good enough' until about 2008 going by the consensus here. So if you wanted a good experience you had to wait a couple of years on the PS3 whereas the Xbox 360 had it out of the box.
5. No matter what people say about it in online forums not only could they get away with charging for Live, they could even increase the price! If it was so unjustifiable and terrible for the majority of people then they would not have had the balls to do that.
6. Xbox Live gives the opportunity for subsidised consoles. People seem to compare only the sticker price of consoles when in reality the situation is completely different when you buy the console. The price of a PS3 vs Xbox 360 isn't $249 vs $269 in the U.S. You have to add a $40 controller and a couple of games which makes the price closer to $500 U.S.D. If you can buy the 360 in the holidays for only $100 down with two games you can easily leave the store with four games and two controllers for say $260 which gives you IIRC Forza, Skyrim, Halo and Call of Duty with Xbox Live and two controllers for multiplayer.
Tease.
