The fact that you even ask shows me that you were not really paying attention to the entire series or the team in general.
1. Only some of the stars showed up in the playoffs outside of Guentzel, Crosby, and Hornqvist.
2. Murray was very unreliable in comparison to his past 2 seasons in the playoffs and season, he just didn't exude the confidence and sully quote word alert "swagger"...
3. Letang's minutes were never managed, which the coach said he would do, when you have a problematic player that needs to be reigned in and you say you will but don't, is it the players fault then? Or is it 50/50 blame share? Hint: The latter.
4. Coaching staff just didn't seem up to the task with motivating the team and finding the right pairings all throughout the line-up. Again, the whack jobs that like to think I am pushing a fire Sully narrative, COACHING STAFF - it implies a collective, a collective of failure this past season.
5. Letang was a problem, yes, but as you see, not the only one.