This is purely speculation, but I suspect the culture gap between Oregon and Miami is a factor.
My family moved to Oregon from Cuba. Great place, we visit all the time, I was just in Eugene for a wedding. But there is no place more different than Miami on the map. The air, the slow drizzle of rain, the chill atmosphere v. the intensity, the fact that everyone is white and liberal. And football is just not as big of a deal.
Cubans come back to Miami if the money makes sense. And remember, Oregon has one of the highest state income taxes in the country. The biggest draw for him to stay at Oregon is likely the roster he assembled. They are set up for success.