I'd love to see some numbers on talent pool from the 60s and 70s vs now. While there were fewer major league jobs then, I'm guessing there could have been more pro players then. It seems like there were minor league teams in every rinky dink town.
And everyone played baseball back then. Now kids start specializing as young as 10-12 with year-round travel teams, etc. Not to mention that very few American minorities play the game now.