I've said this a number of times.
There are examples where they kept some fan favorites around a bit too long, not that each moves was without justification without my supporting opinion:
Schilling (signed him for 2008 at $8M, which was pretty big money, back then)
VTek (although it was VTek who turned down a bigger contract)
Lowell (last 2 years had a -0.1 bWAR)
Youkilis (should not really count, since he did very well for the first 3 years of the 4 year deal, but we traded him during year 4.)
Pedroia (looked like a decent to very good deal to most fans I knew, at the time)
Buchholz (at his age, the deal looked solid. This example should not really fit into the aging players we kept vs letting go, but I though worth mentioning)
Sale (bringing this fan fave back on a longer range deal has just about run out of time for any redemption.)
We let JBJ walk, then made a boo-boo bringing him back.
I do agree, we let manny of our fan faves go, just in time. I don't see this as being an issue with this team over 2 decades, but recently, it seems to be made out to be a bad thing.