I agree with your first paragraph but I still think something isn't adding up. McLellan has gone further than I've ever seen a head coach go in calling out his players for lack of effort and heart. But it hasn't amounted to anything. I don't know, maybe it is as simple as the young kids see veteran players who aren't producing getting pencilled into the lineup every night, so the young kids internalize that there is no room for them to "win" a job, they just have to not lose one.
I'm not sure about the roster construction. Yes, the team has relied on a lot of smaller players, but the team has some big players who just play small. Yes, Soderblom, also Rasmussen. But they have plenty of guys who are big enough to finish checks and just don't.
There is clearly a culture issue. I'm only half joking here, but I think Mac should bring in Dan Campbell for the exit interviews because this team is missing grit.