Need clarification on 'blame' tbh. You can't attribute blame in the traditional sense to the fans for Ashley's actions, he is mismanaging the club by not investing in it and pursuing it's potential, and that is ultimately down to him.
Personally I've stopped going to games and won't go back until he's gone, but that's more down to self-respect rather than hoping it will force him closer to the exit it door, unfortunately I think they'll just be more younger people and ignorant people to buy tickets off him.
The best way to get him out is to expose our displeasure in the media as far as possible so the subject sticks and brings negative press to Sports Direct, which is clearly what he cares about. That should be the focus imo.