If Gill stays, despite IM knowing "he's not the guy," it's very possible they are being forced to think more long term. This is tough on instant gratification and impatient fans, myself included. As others have eluded to, what if LU simply can't get Coach Mr. Right at the present time. What else are they supposed to do? They recognize that a new coach is always a gamble, so it doesn't make sense to go with someone you suspect is only marginally better.
There's a lot of reasons Mr. Right wouldn't want to sign up where we are currently at. Maybe LU is being cheaper than you'd think on the salary (will JJ pay someone more than he makes, serious question?). The new coach would essentially be inheriting a mediocre FCS squad, vs. a mediocre G5 squad that has 4 years worth of FBS recruits as a foundation. What good coach wants to come and trash their record by going 6 / 18 the first two years, or worse (see CCU), for what's already a controversial school in uncharted independent status.
Given this, it wouldn't surprise me if the rationale is that Gill is doing decent enough at recruiting, can at least coach .500 seasons, so they use him for 2-3 more years. Afterwards, we'll be significantly more established in facilities and scholarship players than we are now, so LU will be in a position to make the hire they really want. The downside is that the FBS momentum and excitement will dwindle if we can't somehow do more with less during the transition. The last couple of home games this year had about as much energy as a funeral.