If you were located in the recruiting breadbasket of US prep athletes, and your all-time best player's winning percentage against a predominantly religious/white homebread school isolated in the Rocky Mountains was 20%, you'd have insecurity issues, too.
I've been dealing with that fanbase for 30+ years, and there is not a more insecure group of people on the planet. SDSU is what happens when you create an institution made up of 30K people that couldn't get admitted into the UC system. They want nothing more than to have the academic and athletic track record to be smug, arrogant, and condescending towards BYU (like a UC school!) but there is simply nothing to back them up. And it drives them absolutely crazy.
We've been living rent-free in that fanbase's cranium since the late 1970's.
GO COUGS.