Here are my two cents as somebody who hated the trade.
1) It would be silly to blame losses on anybody in particular when the effort is as as poor as it was last night. The entire team failed, and that's not on Krstic.
2) That said, when if we lose in the eastern conference finals/finals I most certainly WILL point back to the trade as the moment things went downhill. Say what you want, but the trade made us worse in my opinion.
2a) Our starters are worse because what we gained in offense we lost in defense, rebounding, and shot blocking. Just wait until Krstic's offense regresses to his mean of .53 TS%. Why would you ever even give the ball to someone with a .53 TS% when you have four all-stars on the court? You shouldn't. You should just depend on that person for putbacks, rebounding, shot-blocking and defense, all of which Perkins does better than Krstic.
2b) Our bench isn't any better off either. Troy Murphy has been the biggest non-factor ever, and I don't know why anybody expected anything different from somebody averaging 3 points per game FOR THE ENTIRE SEASON. Some people are insane with their optimism. Next, without Semih and Perk we don't have shot-blockers on our bench unit, which spells disaster for any NBA lineup. Pavlovic doesn't do much that Wafer doesn't do. Arroyo is a decent pickup, but Delonte was coming back soon enough anyway, and he's a better option (which also would have made Nate redundant). We got Green, so it's not all bad, but ultimately I don't think our bench will change in overall performance due to talent; it will just get worse until chemistry is developed and players understand our defensive schemes, which might take more time than we actually have.
3) Bringing this back to Krstic, he's key because we're going to have to rely on him, big time. I'm not gonna blame him for every silly little loss but time will tell if he can get it done when it counts. And I have my trepidations.
edit: last word. I actually hate Jermaine O'Neal (and I've never actually "hated" a Celtic player before) but I pray that he comes back in time for the playoffs because I'd rather deal with his putrid offense than let the other team go to the rim at-will and out rebound the hell out of us