I play with a lot of ex-pro players (NHL, AHL, D1, etc) and a large majority of them wear shoulder pads. I assume because their entire career they always wore protection and to them, it is just normal to wear shoulder pads. I don't think wearing protection is always about a persons ability. I can skate just fine, better than a large majority of people I play with, but there are still times when you are in a foot race to the corner for a puck, shoving one another, and sh!t happens. Sticks get crossed, skates get tangled, whatever, and someone goes into the boards.
I'm actually more worried about the lower level players than the high-level skaters. High-level players will know when to back off and to let the other person have the puck in a foot race while a lower-level player will go 110% and many times cause the catastrophe.
Destroyed my collarbone on a breakaway a few years ago. Picked up the puck, wide open just past center ice, and the other player was 5+ lengths behind me. As I closed in on the goalie I stopped striding and the other player kept chasing me down furiously. He then swung his stick from behind into my skates and took out my feet. I fell awkwardly, unable to recover or protect myself, sliding into the goal post and then hit the boards at full speed. I knew immediately that something was wrong when I couldn't pick up my stick. The pain and shock then set in a few moments later.