Jonah Keri's new piece on the Pirates' offseason is amazingly nuanced and mostly spot-on in its criticism, and I urge you to check it out. Keri notes the Pirates' "weird" behavior with A.J. Burnett, then notes that even if they weren't going to sign Burnett (who, to be fair, hasn't actually pitched that well this season), there were other players they could have pursued, like Scott Kazmir and Jose Abreu.
The Pirates' decision to hold Gregory Polanco back was sensible, as Keri notes late in the piece. The potential cost there was far greater than the likely reward. In the offseason, though, the Pirates didn't have a significant budget, and didn't end up doing much with the money they did have available. Now they're coming to the end of a great West Coast trip, their pitching staff has been better recently, and they're about to add Polanco, so it's not impossible they could finally be in the midst of a run toward contention. It would have been nice if they had started the season with better talent on hand, though.