That's a league-wide problem, and frankly the Avs get more than enough power plays to win games. And I still don't understand, to this day, why the Avs look so much better at 5-on-4 than they do 5-on-3. Part of the problem is that Rantanen in particular goes from Mario with the Tanooki suit to Mario with the Tanooki suit when you press down and the B button.
Anyway, back to the refs...
To an extent I completely understand why the refs call the game the way they do. If they called everything players and fans would be jumping all over them for slowing the game down too much. Players are a huge part of the problem--they bitch and moan about not getting calls and yet out the other side of their mouths prefer the refs who "let them play."
And I also see why they tend to try and call a "balanced" game, because if they called it any other way the conspiracy theorists would be having a field day with them.
That's not to say I don't think there's some gross incompetence on the part of some NHL refs, and that I don't think there's a ton of room for improvement. But for things to get better, some universal truths will have to be accepted by players and fans that I just don't think they're ready for.