Doesn't saying Pierce has to retire a Celtic mean you care more about Pierce then you do about the Celtic's organization?
No. I think it has more to do with the fact that:
1) Some fans prefer to watch good basketball for another couple of seasons before going back into the dregs of the lottery;
2) Many of those same fans recognize that rebuilding to a championship-caliber team is rarely successful, and that a wildly successful rebuild would see this team challenging or the Eastern Conference Finals;
3) Red Auerbach himself showed loyalty to this team's aging stars, turning the Celtics organization into what it is. I'm doubtful that anybody would argue that Red didn't sufficiently care about the Celtics organization.