To the OP, I get what you're saying for sure and I can't say I'm a huge fan of that approach. I hated the "we ain't coming back" comment after Game 2 in the 2010 finals. Hated it. I would've much preferred him saying, after they had swept the three games in Boston "we knew we weren't going back to LA...". Just get the job done first, then spout.
I also get that this has always been part of Pierce's game and what gets him going. I think Pierce is a great, great player, but somehow I always felt a bit more comfortable, as far as being able to consistently back up the bravado, when Larry or Michael would say something like that, guys that were at a whole other level...
All the above being said, I still don't think that's why the Nets lost last night. Pierce did his best to carry them, making "a lot" of big plays. The fact is that Joe Johnson and Derron Williams need to carry that team to victories at this point - they need to be the ones coming up "big" down the stretch in these game. I think they're both chokers as far as I can tell.
It's their time, not Pierce's, and I think neither of them delivered - seemed afraid of the moment.