People are pretty good at detecting superficial niceness. It's something even babies are good at, it's hard-wired so to speak and it's basically the answer to the important question "does this person really care, or are they just pretending". Sure, some become really good manipulators and can fool others.
Somebody else could have done pretty much the same VR tour and it would have had a different effect. The technology itself here wasn't the main problem.
> Facebook is generally pretty careful to isolate its CEO from opportunities for bad press, Zuckerberg has an extensive team helping him maintain his manicured public image on the social media site.
The manicuring part is the fake niceness. "Someone is making him look like what he is not, what are they really hiding..." kind of idea. That is it is contrasted with his or his company's action, what he did and said in the past (ex. "They trust me — dumb fucks") and then it becomes unsettling and has a negative effect.