I've never really bought into the whole idea that our identity vanished with the Perk trade... but something has definately changed, and not for the better.
How many times have we heard other players from around the league say that that is exactly what happened? Derrick Rose's quote is one that sticks out in particular, but there have been a lot of other players who have said the same.
http://www.slamonline.com/online/nba/2011/04/derrick-rose-on-the-celtics-we-know-we-can-beat-them/ With Perkins gone, everything changed for the Celtics and they knew it: the toughness, the tenacity, the presence in the post. “He was tough,” Rose said. “We could defend on someone that was big. He was really tough to go around. … They’re different.” Different doesn’t mean better. It means diminished. The Bulls beat the Celtics 44-22 in the paint, beat them badly on the boards, too. They assailed the Celtics the way the Celtics used to assail everyone else. “We know we can beat them,” Rose flatly said.
How 'bout old friend Tony Allen?
“I guess they wanted to get more offensive-minded,” Allen says. “They got rid of me, and, well, now who do you get to defend the perimeter? OK, you guys got shooters. Now you get rid of Perkins, and who sticks the best post man? Who sticks Dwight [Howard] and Amar’e [Stoudemire]? Well, I guess they want to spread the floor a little more. I don’t know. It all caught me by surprise. I guess they want to be more of a shooting team than a defensive team.”
Can't find the full quote, but he also talked about the hesitation he felt driving the lane against the Thunder, knowing the big guy was down low waiting.
There's been a lot of these little comments, I'm sure there will be more when the season's over. The C's aren't feared anymore. They rolled over the Knicks because the Knicks were a D-League team plus Carmello. No one else is really afraid of them, anymore.
Surprise, surprise, you get rid of your most physical player and second-best defender, there are negative consequences.
EDIT: Not going to spend all night looking, but here's a quote from another old friend, Scalabrine, about how his Bulls teammates reacted to the trade:
On Perk: "One thing I always did when I was there, is I trusted Danny and Doc and the decisions they made and I always thought they were smarter than us and smarter than me. I will say this: As a whole our group is pretty excited about it. [Teams around the league] were excited to hear that he was gone. Truth be told, you know, moving forward and watching this team play you don't know what's going to happen." ... Derrick Rose was like 'Man, this was big for me. I can get to the basket.'
http://www.iamagm.com/news/2011/04/08/mr.opinion.brian.scalabrine.says.bulls.were.ecstatic.when.celtics.traded.perkinsWhen your opponents are ecstatic about you trading away one of your players.... yeah, that's going to have an effect.