The veteran players on the team did not have the intensity level necessary to beat the Islanders. It wasn't an issue of youth. The third and fourth lines were our most effective start to finish.
I don't think it is an intensity issue, but a fatigue issue. The top guys are logging too many minutes in these games. That in part is because the 3rd defensive pairing is bad and Quinn does not trust the 3rd line to hold it's own. The game on Sunday was a back to back and he leaned on his top 6 and top 4 defense too much. You go into that next game against a much better team, not on a 3rd in 4 nights, and you've got a top 6 and top 4 that is gassed. You also cannot roll your 4th line with Howden on it without getting your shit pushed in.
Quinn needs to trust the 3rd line more, especially when they have a lead. If he cannot trust that line, he needs to change that line. There is no reason that in a 2nd of back to backs against the Devils that Lafreniere is getting 9 minutes, Chytil 8 minutes, Kravtsov 10 minutes, and Kakko 11 minutes. Fox played 27 minutes on Sunday. I love that Fox is the guy on defense. It bodes well for the future of the team. It doesn't bode well for this current team that he has to log that much time in a game against the Devils on the 2nd half of a back to back.
In a normal regular season, the schedule is not condensed. You have off days to rest these guys. There is a reason why teams with actual depth are at the top of the league this season, it's because by now if you have been leaning on your top guys every single game, they are going to be exhausted. No matter the level of conditioning they have, that will be the case.
Moving forward, this should not be an issue, but right now, it's probably the biggest reason they are in the hunt for a playoff spot, but the reason why they won't make it.