Excellent points. I've personally seen Wrestling shows moved or postponed for a week to accommodate the NFL in particular. It makes sense, (although I'm not sure it was the same in 1997, when WCW was pulling 9m+ viewers on TNT)
I'm sort of glad we have it the way we do when it comes to this sort of stuff. Continuity in the episodes, mainly. Imagine if Premier League football affected where TBBT would end up! There's matches Saturday, Sunday, Monday and Wednesday in some weeks, with the FA Cup on Tuesdays also, and Champions League games, Championship games on Fridays...