If you're the BOT and you're looking at athletics--specifically football--as an investment, I think they're doing a pretty great job maximizing their return relative to their investment. Whatever positive returns are associated with having a football program, I don't think you'd double those returns by doubling the expenditures on the program.
To be clear, I do think that spending more money on the program would make it a better program in terms of W/L. And I do think that a better program accomplishes the goals of the BOT more than a losing team does. But relative to all of the other potential investments out there, I think the BOT is probably okay with level of resources allocated to BYU athletics.