I don't know about "nothing to gain", necessarily. There's reasons for each type of team on the schedule.
FBS - we get $
"lower" FCS (like a Pioneer League team...Valpo, Drake, Butler, etc.) - easy win, but unless we do a H&H agreement with them, we have to pay them $ to come here.
Upper level FCS team (like the Big Sky teams) - makes our schedule tougher...I know that sounds like a bad thing, but SoS is taken into account with regards to making the playoffs
In 2015, for example, we played then #25 ranked Eastern Illinois (won), played Illinois (lost), and played at then #1 FCS Coastal Carolina (lost a fairly close one). We went 5-3 in the conference, finished 6-5 overall and 5th in the conference, but became the first 6-5 team to ever make the the FCS playoffs as an at-large (I think a team had that record and won their conference one year to get their autobid...NEC maybe). We got picked ahead of quite a few decent 7-4 teams like Northern Arizona, North Dakota (they were really pissed about that one), Towson, UT-Martin, Western Carolina, and Central Arkansas. UND was especially mad because they'd actually beaten FBS Wyoming that year. They'd gone 5-3 in-conference like us (although Big Sky, as opposed to MVFC). But because we had the #1 toughest SoS that year in the FCS...we got the spot instead of them.
We also have the MVFC/Big Sky scheduling agreement in place, and I don't know what the terms are for that. Like, if we have to schedule a Big Sky team every year, or what.