I agree for many sports, that is the biggest factor. Baseball though? I think the biggest factor is the cultural issues. Physicality plays far less in baseball compared to strategy and little things that women can pickup just as easy as men.
I disagree. Women are weaker, smaller and slower. That's just science. Baseball is all about strength and speed. Being slower, weaker and smaller is a huge disadvantage.
In the 100m sprint, the fastest women are a full second (+10%) slower.
Take tennis, for instance. Serena Williams is by far the greatest female tennis player in the world. I bet the top 200 ranked men in the world would beat her quite easily in a match.
Physicality doesn't play a role in baseball? Do you follow baseball at all? Look at the size of these players. The average MLB player nowadays is built like a tank and incredibly strong. The average MLB player is 6'2" and pushing 200 pounds. That's a big lady! Pitchers are routinely 6'4" and 6'5" and 220, 230 with very long legs and arms. Why do you think it's such a big deal that Marcus Stroman is so good at a modest 5'8", 180 lbs? Because that's pretty much unheard of nowadays.
Sure it's possible that the Danica Patrick of baseball comes along and makes an impact, but there is much more than cultural issues holding women back.