Disastrous is pushing it.
It was an interesting gamble. He's got a lot of tools, he's talented, seems to have a great attitude. Unfortunately, they rushed him to the NHL when he should have polished his offensive skills against competition he could handle.
Mishandling a high pick like a bunch of amateurs is obviously a setback. He'll still be a good player and I expect improvements but the subpar development will leave some marks.
Cooley is great and he was developed smartly. The paradox is that, when you don't rush players and let them take the smart path, they actually blossom sooner.and achieve greater potential. That's a lesson for the Habs brass (and a whole lot of posters on the Habs board who are only beginning to realize what happened).