I think this question is really more than one part. The first is very easy: who is to blame for rebooting the canon? The answer would be Disney and the Story Group; they are the ones who decided to flip the switch and start again. Now I am not saying that is a terrible, evil thing. It's what happened, and while I may not like it I could understand why. The previous iteration of what is now the Story Group gave reconciling everything to canon a valiant effort, but there were plenty of inconsistencies. There were also an equal number of garbage works to gems in the EU. As much as I would like to, I cannot fault them for wanting to start again.
However, we have to ask ourselves when the plan to reboot canon really began. I propose that it had begun when The Clone Wars was released. Let's just take a quick overview of the things TCW did:
Completely rewrote Mandalore and the Mandalorians
Completely rewrote Dathomir and the population thereof
Completely rewrote how lightsaber crystals work
Attempted to bring Durge in, only he was going to be human, not Gen'Dai
Killed Even Piell
Those are just the ones I can think of offhand. It's clear that even then there were plans to completely rewrite canon, most likely even leading to a reboot anyways.
The more in depth question lies in who is to blame for the distressing turn this new canon is taking. Let's examine each of the valid entries on the poll and see if we can identify the source.
George Lucas: the man takes enough flak for stuff as it is, and while he can be credited for some ridiculous things in the new canon (requesting they bring Maul back to life for one), he isn't in control anymore, so he is most definitely not to blame. Him selling Star Wars to Disney was a way to keep Star Wars alive and thriving, and there is nothing wrong with his intent.
Dave Filoni: the guy's done more harm than good for Star Wars. He succeeded in wrecking a lot of canon before the reboot was announced. However, he doesn't have a hold on all the aspects of the IP, nor is he in complete control of what happens, so he can't be the problem.
Us: yes, I will admit our rose-colored glasses of nostalgia is most likely blinding us to some of the good in the new canon. However, I have spoken to many of my friends who have had absolutely zero exposure to the EU and they are also dissatisfied with the direction Star Wars is headed.
Story Group: they are working on the new content, so it must be their fault, right? Not exactly. They were actually formed about two years before the canon wipe. The decision to wipe and start again, though executed by them, did not originate from them. In addition, their job isn't to write Star Wars, it is only to determine canon and ensure no parts of the new canon clash in the way the old canon did.
Disney: the Big Bad, the Evil of all Evils, the one we dare not speak of. Surely, as we have reached the end of the list they must be the ones to blame! Well, yes and no. It is true that the executives and the like are the ones who end up approving what happens, in the end they are looking at what will net the most money, and while this is definitely sad, they have a bottom line they are trying to hit.
No, the real problem is modern society. Today's culture wants shallow. They want action without substance. They want effects over form. No story, and predictable. That's why reboots are the in thing, because people already know what's going to happen. That's why movies like the Avengers are such a big hit: a 2 1/2 hour fight scene without a plot doesn't require any brain power to comprehend. You even see this trend in video games, with the fall of strategy-based games and the rise of the modern FPS. Any entertainment that dares to go against this has a tough battle ahead of them. It is just more profitable to make what people want to see. Thus if ever a change is to happen, it has to be with the audience first. When the companies see the audience wants something more than cheap, lifeless rehash they'll give it to them.