Because winning as a head coach will get you offers much quicker to become head coach at a bigger school. This seems like a pretty common practice for coaches working their way up the ranks.
Look at how many coaches have a good 3 year run at MAC schools then get called up to coach at a much bigger school. What made those guys want to go to a lowly MAC school? I think it's the same thing that would make them want their own program to run at Marshall.
I mean hell, anyone who's worth their salt should be able to look at our weak conference, our facilities, current stock of players and think to themselves, yeah, I can be successful there.