IMHO,
- Football. At one time, WVU was drawing something like 30 to 40K, including students who don't really pay. (Spamites, yes, this is true, and, no I don't believe lap dog media reports that made fantastic unaudited live gate claims, thoughtful people can tell what %age of a stadium with a known capacity is being used, just stay out of this). And WVU (still, but morso in the past) adjusted ticket prices based on demand. MU represented a full house at full price. Further MU represented a very sellable TV game.
Today, WVU is getting a 90% or so sell out, and is getting plenty of money from the Texas-Oklahoma conference TV deal. They just don't need us anymore.
As one of the Little 8, WVU has 3 games cover each year. It wants two P5 or AAC games home and home, preferably from the AAC or the bottom half of a P5 conference; and a for-cash no-return game versus a I-AA.
MU has 4 games to cover per year. The general pattern is a mix of step-up games played for cash with no return, even up games versus the MAC or Sun Belt, and home and home deals with name schools (Purdue, Cincinnati, Louisville, Boise State, Navy, etc.) And a I-AA, to give 7 home games and make $$. Frankly, we make way more money playing the likes of Notre Dame, than WVU pays a I-AA. And we can get good teams like Boise State and Louisville in here. We just don't need them any more either.
- Basketball, From the end of WVU's run in the late 50s/early 60s to the early 80s, Marshall was equal to WVU in basketball, if not ahead. Basketball was not that big a deal there anyway, and they NEVER filled their over-large building until they finally agreed to play us. The home and home series was a good deal.
This devolved into a Legislature ass-kiss deal played in Charleston. And national and local TV deals made it be played on weeknights. Still fun, but not as fun. We spent the 90s and 00s in the wilderness, while WVU built itself into a solid second tier national team. Yeah, we won every 5th or so year, but that is the nature of basketball. We just were not competitive for a very long time, and probably won't be on their level most years in the future. To make an analogy, at one time MU-WVU was UK-Louisville or IU-Purdue, or UNC-NC State. Today it is more like UK-Western Kentucky, or IU-Ball State or UNC-UNC Greensboro.
The $$ and the competitiveness of MU-WVU do not work out in the two major sports (and also not in women's basketball, where WVU is likewise just way better). We should play in soccer or baseball or whatever, and let it be. It is part of the past.