Most disappointing offseason ever?
Not by a long shot.
Ok, other than len bias.
Len Bias 1986?
How about the brutal 1997 off-season? Losing the Duncan lottery, blowing the #3 and #6 pick, throwing away our cap space on Travis Knight and other stiffs? Letting David Wesley and Rick Fox walk for NOTHING?
How about 2001? The team clearly could've built a title contender that off-season with the right moves. 3 first round draft choices in a LOADED draft and whiffed on all of them. Then they could've traded Antoine and one of the picks to Chicago to get Elton Brand AND move up to the #2 pick in that draft (coulda had Chander, Gasol, Battier, etc). With Pierce in place, and solid role players - and a ton of flexibility with a good trade chip in Antoine, and 3 firsts in a stacked draft - the Celtics could've easily had a legit contender from 2001-2006 if not longer.
Those were the worst. This doesn't come close. Last deadline was the real killer.