I'd like to know who the many are who referred to it as a "gimmick." They made asses of the themselves.
When Dennis was hired at Miami, Terry Donahue, then the highly-respected coach at UCLA, called Dennis' offense, the "best conceived" offense in the Pac-10.
Dennis himself said they watched a lot of Redskins film to design the WSU one-back offense. That one-back, with John Riggins as the only RB, was no gimmick. It was a dominant NFL offense.
I don't know who would call that offense a gimmick. It's rare that a one-back offense would have TWO 1000 yard rushers on the same team the same year. That's exactly what Erickson had at Washington State the year before he came to Miami.
Dennis was one of the hottest young coaches in college football when we managed to get him.