You are so clueless sometimes that it is hilarious.
First of all, Joe is right. Fox has a national television window on Saturday at 1:00. The two regional games are Cubs - Astros (Pittsburgh gets this one) and Red Sox - Blue Jays. However, no where did I ever say that MLB teams are not allowed to start a 1:00 on all Saturdays, or even any Saturday other than this one. Fox has different national television windows on different Saturdays. Some Saturdays Fox doesn't have a game at all. There are other times when Fox is showing a national game but they do not have a guaranteed national window, so other teams can broadcast their games at the same time Fox is showing a national game. There is not one solution that fits every Saturday. It varies from week to week.
If you want a few examples, the Pirates have played three Satuday home games at 4:00 this year. On every one of those Saturdays Fox had a national window at 7:00. 4:00 was the latest the Pirates could start and still televise the game. So that is when they started. On the other hand, the Pirates played three Saturday night games (that I can think of off the top of my head) that were Fox national games. The one at Texas in May, and then two games in June against the Cardinals and the Dodgers. There may have been one or two others (maybe one of the Cubs games earlier this year?). but there were at least three for sure.
Secondly, for someone who claims to have studied economics and claims to understand economics you sure are clueless as to the way that economics works in the real world. The Pirates have, and always will have, precedent over Pitt for the parking lots because the parking lot operators make a lot more money selling parking to Pirates fans than Pitt fans. It isn't even close. If you really can't understand why the Pirates are number one on the pecking order then you surely must have failed any and all economics classes you've ever taken.
Thirdly, I suppose it would be possible when there was a 7:00 Pirates game for Pitt to say screw it, we don't care, we are playing at 3:30. But the upshot of that isn't that PIrates fans would have no where to park on the North Side. The upshot of that would be that Pitt would not be allowed to sell parking passes to that game and Pitt fans arriving on the North Side at 10:30, or 12:00 or 2:00 for the Pitt game would find all the lots closed. Because THE PIRATES TAKE PRECEDENCE. As anyone with even a minimal understanding of economics would be able to guess.