What? The vast majority of his playing time was in the Original Six, when the league was very, very, good. Post expansion(1967) there was a definite dearth of talent, especially on the expansion teams. Scoring stats shot up due to the weak sisters in the league at that time.
What you're referring to is about the number of NHL teams. In the Original Six, with only six teams, the talentbin the hockey world was certainly more concentrated, and, largely because of this, and the smallness of the hockey world, the NHL was stable and generally good.
But what I'm referring to is the overall talent in the sport. The top-end talent and especially the depth of talent wasn't very strong at any point in the O6. It just kind of seemed like it was because there were only six teams. The talent did certainly increase somewhat over time in those 25 years. The '60s had a lot more talent than the early '50s, which was pretty weak.
But if you compare, say, the early '60s talent to the early to mid '70s, there's a lot more depth of talent in the latter. It looks different because, rather than being spread over six teams in the early '60s, it was now spread over 30 or 40 teams, or whatever....in the NHL, WHA, Soviet Union, Czechoslovakia, and Sweden, and a bit in Finland.