As fans, we always have a propensity to blame management and coaching. The reality is that there is plenty of blame to go around. Without question we have a collection of very good players that should be performing better. It's hard for me to blame management when they were able to draft and develop both Rudy and Donovan. Most teams over a ten year span are lucky to draft one guy at that level. We drafted two. All the other ancillary moves didn't get the job done, but again, management gets an "A" simply for landing those guys in the draft. I'm not sure anyone could have done better with the secondary moves, it's all hypothetical anyways. As a fanbase, most of us were stoked to land Bogey, Conley, etc. When your two best players hate each other (apparently), it's hard to overcome the chemistry issues that creates (unless your Kobe and Shaq).
Blame it on Quinn? Maybe. It's possible he's just better suited as a coach that is great for young players, implementing a system to help them find NBA success. Hard to judge, but he definetly has been outcoached in the playoffs for two consecutive years.
I think we have two options. Do a "half" blow-up by trading Gobert, Conley, Bogey, and any piece that makes sense with the exception of Donovan. Move Donovan to PG full time, and build a balanced team around him (mulit-dimensional players). This option might need to include a coaching change. The other option is just to blow everythign up, and plan on sucking for at least the next few seasons.