Just looking from a distance, I think Biggs' point about lack of a brand is significant. Recruiting today is about identifying with a brand. You can pick almost any brand and find kids who will identify with it, but having no brand at all is the kiss of death...it equates to having no reputation. When they left the conference that included the Texas schools and moved to the conference that includes Chicago there was somewhat of a shift in their audience. I don't know if they shifted recruiting efforts to match. And sure, everybody goes to Texas and they can, as well, but they don't have the program visibility there that they used to have.
Frost may be a good coach but a poor recruiter. Or maybe he doesn't hire enough recruiters on his staff. It's not like he has no budget for assistants, so it has to be more about the choices that he has made than the financial limitations with which he has to work. It is even possible that he is not that good a HC. I am not close enough to know, but I suspect that after this season his seat will be very hot, and if there is not improvement there will be a lot of calls for him to be replaced. Moos may avoid that...given that a condition of his hiring in the first place was that he would immediately hire Frost. Time will tell.