I grew up in Oregon. My sisters are Ducks. My neighbors have a big party for Ducks fans every game day. Many Ducks fans are not enamored with Cristobal. They think he fell *** backwards in the title game last year and loses too many games to teams he should easily beat. He will always fall short of the playoffs. Mario built something good but they think he's reaching his ceiling and they need a different coach to finally put them over the top. Are they spoiled and unlikely to find a better coach? Probably. But IMO he's not as popular in Eugene as you may believe. Doesn't mean he'd come to UM though.
I disagree with saying Oregon is a better job - as has been pointed out, 3 years ago a mediocre UM team, even with the loss to Pitt, gets into the playoffs with a win over Clemson. A 1 loss Oregon is already out of the playoff picture this year unless some craziness occurs later in the season (they probably get jumped by a G5, Cincinnati, when the BCS rankings come out). This year a minimally competent HC would have torn through the ACC coastal (Pitt might have been the one tough game in the regular season) and played a weakened Clemson in the acc championship. An ACC champ with 1 regular season loss still has a realistic shot at getting into the playoffs. A Pac12 team has to run the table. So depends on what you want to weigh when saying which job is better. Oregon has resources and money. Big plus, of course. Right now he has a lock on Cali recruiting, but USC can take that advantage away depending on who they hire. Other downside is Oregon has zero margin for error. One regular season slip and they are out of the playoffs. Call it an east coast bias or whatever you will, but a team still having control of its playoff fate despite a regular season loss (in most seasons) is attractive to a lot of coaches.