Well, I'm not sure Monmouth has anything going for it outside of (a not too impressive) RPI, either. It's ranked #67 by KenPom, #81 by Sagarin. Even going by RPI, what is really the case for a team whose best wins are over #32 and #48, and has losses to #209, #220, and #231? (As compared to say, Michigan, whose best wins are over #14 and #15, and worst three losses are to #35, #42, and #72.)
These teams don't always "lose out to the big boys," and when they do, it's usually because they don't deserve to be there.