I hate when people say this.
Total viewers ALWAYS has been the #1 thing. However, when you have a home team in a major media market, it provides a sense of security to advertisers that
a) a significant number (to advertisers) of people in that city will watch their home team
b) a smaller number (but still significant) of Home Team fans in that city will begin to watch conference games not involving their team because they now have a vested interested.
What's the best way to prop up your "total viewers?" Ding, ding, ding, you add a team from a major TV market.
Adding a school like WVU is risky AF because although, yes, they have a big fanbase relative to their media market, they have no room for growth. WVU isnt winning any new fans in Morgantown or Charleston. They're already fans. If Temple goes 10-2 1 year in the ACC, all of a sudden, they get massive ratings for that year and some come back the next year.