Something called loyalty.
I don't know whether others care or not, but it's hard to see your team trade two guys who gave their all for your team to some other team just so you can be good. That is incredibly selfish and just not right. In fact, I'd rather be bad for the next couple of years knowing that even though I ended up trading Pierce and KG, that they are in fact a better place than this team and that I at least returned a tiny bit of what they gave to this franchise back to them.
Just remember one thing: Pierce didn't look for his own benefit when he saw that the team was bad and was going to stay bad (like we look for our benefits by trying to send him away in all possible trades) and that KG brought a culture to this team that still remains and will remain in the future as well as built players into what they are (Perkins, Big Baby, RONDO, Bradley, helped Sully and countless others).
It's very easy to forget everything and look for your own benefit, but let's show a little loyalty and support to guys who sacrificed for the better of this franchise.
Let's not forget that Paul Pierce and Kevin Garnett could have done what Ray Allen did and go to the Lakers after they lost in 2010 Finals or go to some other definite contender. They had tons of opportunities to do this.
These guys gave importance to every single game, giving their heart out, whether it was against the Bobcats or the Heat. They played through injuries and in some cases, forced their way back from an injury (KG in '09 was pushing all out to get back from his knee injury until he was forced to be out for the season).
It amazes me how easily we forget all this and start looking for our own benefits. It amazes me that many of the "Celtics fans" have no loyalty whatsoever.