I don't think it was development as much as poor scouting and drafting. Galchenyuk,McCarron and De La Rose in particular were all horrible hockey players and should never have been picked.
At the time Galchenyuk was the obvious choice, Reilly is the only alternative discussed and he generally wasn't considered top 3 at the time. Who would you have taken instead of De La Rose? Lehkonen? They drafted him anyway. McCarron was a reach but there just aren't that many great scorers available in that draft. Some D but not that many, and not that good. The habs had some bad drafts but those particular picks didn't hurt them. I'd say the problems with habs drafts are:
-drafting for need (McCarron, big slow defencemen)
-trading picks/young guys for older players. With the cap the early years are worth more than the late ones
-bad drafts in years they had high picks. Compare top 10 of the 2012 draft to 2011 or any of the more recent ones. Unlucky, but should have taken D.
Romanov has been great and would be better if the D as a whole were better. Weird that Edmundson looked so good early, but I guess Vancouver is just that bad. Longer term Romanov is one of the few D likely to be good. Weber is old, Chiarot and Edmundson are limited, Petry is sort of old, Kulak is so-so, and Mete could go either way. Have to hope that Fleury and Brook recover from bad seasons, and that Harris, Struble, Guhle, and Norlinder have smooth pro transitions.