Notwithstanding eras with competing leagues (WHA, PCHA, etc) or World War Two, the
Canadian talent pool has been remarkably similar over time.
Here's a chart showing regular NHLers as a percentage of Canada population, based on C2SR's numbers.
Year|NHLers|Population|Proportion
1921 | 34 | 8.8m | 1 in 259,000
1931 | 130 | 10.4m | 1 in 80,000
1941 | 98 | 11.5m | 1 in 117,000
1951 | 99 | 13.7m | 1 in 138,000
1961 | 100 | 18.2m | 1 in 182,000
1971 | 245 | 21.6m | 1 in 88,000
1981 | 371 | 24.8m | 1 in 67,000
2006 | 574 | 32.2m | 1 in 56,000
The number for 2006 should be doubled since Canadian only make up half the league now. This means that 1 in 112,000 Canadians make the NHL today, which is actually a
higher rate than during the Original Six era.
On the main boards we see people trash Shore because there was "no competition" for the Hart. Considering his era roughly spanned 1931 to 1941, we see that Canadian made the NHL at only a slightly lower rate than they make it today.
Obviously these are rough estimates, but the numbers make sense. The Canadian talent pool was higher in the Original Six era than it was today; there are more than three times as many jobs to go around today (for Canadians) and the total population has only doubled.
When people say that there are so many quality NHLers nowadays, they forget that there were literally only 100 jobs available during the 1950s and 1960s. Canadians made the NHL at roughly the same rate then as they do now. The huge amount of talent, good enough for the NHL but not in it due to the lack of jobs available, is also shown by the fact that when the NHL doubled, there were enough NHL-calibre players to build (mostly) healthy, sustainable franchises.
The overall talent pool is higher today due to non-Canadians in the NHL, but the question is: have the number of new jobs created through expansion outpaced the population growth from all countries? The only was to really estimate this is to look at the percentage of advanced junior/semi-pro hockey players in each country, in proportion to the jobs available today.
(Two quick technical notes: I'm defining "regular NHLer" as a player that appears in more than half the schedule. Of course, it would be useful to look more specifically at the percentage of Canadians playing hockey. If Canada's population is higher now due to seniors living longer, that doesn't really add to the country's ability to produce NHL players).