Wow...a lot of revisionist history, 20-20 hind-sightedness, and current short-sightedness in this thread.
The only 'punishable' mistake he's made was re-upping Bylsma after last year, but I think that he valued stability over a 'fresh' voice in the lockerroom. Bylsma is/was a highly thought of coach that was tapped to coach team USA...showing that the respect for him extended past the Pens organization. Last year's Bruins series was tough to take, but not on the level of the Flyers series the year before. I think Shero was more concerned that an overreaction would be more damaging to the team than a 'stand pat' attitude. The truth is that we'll never know. The grass isn't always greener, and sometimes the devil you know is better than the one you don't. IF Dan did lost the room (which it appears that at some point he did), Shero should've made a move right away...unless it was either very late in the season or in the playoffs. At that point, what do you do?
I love that people are praising Ray for his trade savvy, but killing him for his drafts. They are not mutually exclusive. Ray hasn't drafted for organizational need, he's drafted for assets. Those assets can either be developed to help this organization, or used in these masterful trades that he's been known to pull off. Puck moving defensemen are valued and coveted by virtually every team in the league. Shero's plan has been to use his draft picks as chips to bring in other pieces. Could he have drafted an impact wing or two? Maybe. Could he have drafted an impact wing or two picking where the Pens usually pick? Doubtful. He's trying to stockpile valuable assets. I can't say he's failed.
Was the team big, tough, and nasty this year? No. Was this because, philosophically, Shero is against that type of team? I don't think so. The man went out last year at the trade deadline and brought in Brenden Morrow, Jarome Iginla, and Douglas Murray! That is big, tough, and nasty...and it didn't work. The team never gelled. It got too slow. The roster was littered with skill, leadership, grit, toughness, experience, etc...but it wasn't enough. Did you really want him to do the same thing again this year? Of course not. We wanted speed and size. So does everyone else...but we were up against the cap. You can't just go out and pick people you want. Doesn't work that way.
Is he perfect? Absolutely not...but I think he's still a top 5 GM in the league right now. Firing him because he stuck up for Bylsma last year would be the definition of cutting off your nose to spite your face. Root out and eliminate the real reasons behind these 'hideous failures'. It isn't the GM.