UCF is the nation's largest commuter school. This is not something to brag about. Athletically, last year's 0-12 season is the opposite of growing, in the minds of anyone with logic. Nothing could be more opposite of growing than to be the cellar dweller of your conference. And UCF's fan attendance is certainly nothing to write home about either.
UCF is in a state dominated by the University of Florida and Florida State University. Outside of professional sports, UF and FSU, no one has any interest in UCF (except Knights fans). So UCF growing its "footprint" academically and athletically is irrelevant. No power conference would consider UCF as a prize to go after. Otherwise, UCF would have already been in and it wouldn't have to rely on some guy from the Orlando Sentinel to post such an article asking for the Big 12 to consider UCF, with USF as a possible travel partner. This reminds me of the time when BYU's Bronco Mendenhall pleaded for a Big 12 invitation, with Boise State as a possible travel partner.
These days, "directional school" conjures up an image of a school that is and should remain mid-major. That is just the way it is. Is it snobbery? Yes, I would agree with you on that point. It shouldn't come as a surprise that fans of power conference schools tend to be snobs.
Everything you've posted (about the "measurables" being there), that is the same argument we see from fans of other AAC schools. UCF is no exception here.
Right now, if you were to visit a Big 12 Conference message board, you will find very few to none supporting UCF for Big 12 membership. In fact, UCF is barely mentioned. We don't hate UCF. We just don't see UCF as a good fit. Remember, we aren't speaking for the conference itself, we are just voicing our opinions on the subject.