I believe the Habs have a good roster, with chemistry but had bad luck with injuries - Drouin, Gally, Byron, Armia, Mete. This season is waster but the roster is not bad and the prospect pool is quite good (KK Poehling, Suzuki, Ylonen, Romanov, Brook) even though there is no Crosby/McDavid material !
Given the state of things, it is for sure that if Bergevin went for a rebuild, he could get 3 1sts by trading Tatar, Petry, Price. Does this make your team greater ? Not sure but what is certain is that it delays any possible playoff run and most likely the next GM reaps the benefits of these moves.
To those criticizing Bergevin's trades, this is quite unfair, I do not see any very bad trades since he has been there (Danault, Petry, Tatar, Suzuki, Weber are all great acquisitions with more value now than when he acquired them) Main mistakes were poor drafting and issues with UFA signings and extensions (Radulov out, Alzner in, Price contract) and the lack of consistent strategy regarding the window the Habs were targeting (IMO a playoff run every two year is not a sign of clear franchise strategy)