Yes, in the past 20 years, the quality and participation in the ACHA has dramatically increased.
Another distinction to add would be that back in the 1970's, even the very early 80's, players still went to college for the education versus playing in the NHL.. If you wanted to play hockey professionally, you went the Canadian Major Jr route.
Very few of the 1980 US Olympic hockey team had long NHL careers. Morrow and Broten mainly come to mind. The club and ACHA structure wasn't very widespread then so who knows who was missed talent wise?