ILVBB, with all due respect, you are way overthinking this thing. Baseball is a game that attracts tens of millions of people every summer. Always has, always will. Attendance this decade is way ahead of attendance in the 90's.
I don't think the parent/child experience of attending a baseball game together can be replaced by any other sport. The relaxed atmosphere of a summer evening at the ballpark with your toddler will always be a right of passage for young parents, hopefully creating new fans from each generation.
Like someone else said football is a perfect TV sport. Rectangular field fits perfectly into our rectangular televisions, perfect view of every play and you get to see every play 2 or 3 times. Plus you can watch two or three at a time. NFL has done a good job exploiting that.
It does not mean people have stopped watching or attending baseball games. Baseball is not going away anytime soon.