They have not "lost the fanbase." When training camp comes, it will be packed to the gills with fans spending money on Titletown. Family day will be packed again, and opening day will sell out just like every home game.
The fanbase might be upset or disappointed, but the coffers and stands are full. Ed Policy has very little reason to move on. The Packers have no first-round picks for two years and a messed-up roster with cap issues...why the hell would Harbaugh or any other coach want in right now?
If you take the emotion out of it, Green Bay took a risk with Parsons, and it backfired. But Gute oversold his roster, and it shows big time. None of this is fixed by a new HC alone.
GB isn't going to blow it all up to make the X and message board fans happy, and IF they do, we will be out of the playoffs more than in. Emotional decisions rarely, if ever, age well in the NFL.