It's time though. I'm tired of the rinse and repeat cycle for young kids wherein they come in, get a lot of icetime, do fairly well, then get recycled to the minors or bottom 6 roles throughout their career.
This is why I wasn't as critical of DW when he traded away picks/prospects and moved up in the draft so aggressively. Not because the Sharks mishandle prospects, but because their hands have generally been tied by the quality of their top forwards.
For more than a half-decade, the Sharks have had Thornton, Marleau, Couture, and Pavelski
solidly in the top-6. They've had players like Clowe, Havlat, Heatley, Burns, and Michalek filling out the other positions.
That is the hurdle a young player has to cross. And given that the Sharks have been a competing team, he doesn't have much time to do it; he pretty much instantly has to jump in and start contributing. Hertl and Donskoi were able to do it, partly because of weaker rosters those particular years, but few are going to be able to do it. I'm not sure how Goldobin, Coyle, Bonino, Boyes, Mcginn, etc. would have developed in San Jose with few chances to grow.
Also, I'd question the potential of some of your listed players. Do you really believe that Karlsson, Tierney, or Nieto could ever leapfrog over those other players? Not to mention players like Boedker and Ward! I can't see a world where Chris Tierney forces Logan Couture out of a center spot. I daresay it looks like Tierney is going to be the #3C this year, and he's likely to be overwhelmed.
Looking at the current "sans-Marleau" roster, I can see Labanc and/or Meier having more opportunities and chances to grow. On defense, I can see where Heed, DeMelo, and Ryan can at least get NHL time. From that perspective, giving spots to those players is good for the team's future.
But, I think we can all agree that if the Sharks were solely focused on being more competitive now, keeping Marleau, acquiring someone like Radulov, and keeping Schlemko would have been the better short-term strategies. Maybe it leaves Heed, Ryan, and Meier in the AHL and Labanc on the fourth line (if that), but that is a more competitive, less risky Sharks team.