Well, my impression is that the great talents of that era had to struggle to get any recognition to speak of in Canada - until, of course, they had success in the States - and then Canada was all over them. There was a reason the 'Canadian content' regulations were brought in - and even then, many radio stations resisted them. CKLW (Windsor), which was one of the most influential radio stations in North America, apparently, fought them tooth and nail.

Canadian culture may have played a role in creating those talents - but not much of a role in supporting them when they could have used the support.

Now, with the Can-Con regulations, we do see musical acts who are big in Canada without much of an international profile (e.g., Tragically Hip), so ... that's a change.