Two things:
a) Once the ACC and WF accept a bowl's required ticket guarantees (which will happen), the how you travel issue is essentially irrelevant. Agree that the Belk Bowl would rather have UNC or State (or Clemson, but they aren't going to Charlotte for a bowl this year) because not only would they meet the ticket guarantee, their fans would buy additional tickets. Outside of those two programs (State may not be bowl eligible and UNC may get a more high-profile bowl invite; however, the Duke loss hurt those chances), there is no other ACC school that would offer a more attractive option for selling tickets for Charlotte.
b) Once the ticket guarantee is accepted, each Bowl's priority is TV ratings because that determines the payout from ESPN in future bowls.
So, it's not the ticket sales that drives the bowl committee's selection; it's which team will draw viewers. FWIW, no ACC team is going to bring many fans to El Paso, Shreveport or Detroit (or many of the other bowl locales); so, the bowl that selects WF or passes over WF will not be concerned about ticket sales.