I don't think what car he was driving was a factor at all. He had incredible wealth even before this, driving a cheap old car is effectively just a stunt to promote a specific kind of public image. Which is fine, but it's somewhat irrelevant.
The change happened because FB didn't internalize quickly or deeply enough that the mindset that got them to defeat MySpace wasn't the mindset they needed to become a trusted service for the long-term. Obviously yes it still exists but it's an absolute shell of what it could have been had this not been squandered -- which is the point that the parent comment was addressing.
I know like three people who bought cars they couldn't park near their employees in good conscience, and I think there's a point where obvious disparity starts doing things to your brain.
Almost like a "I don't owe, but I should pay more, but I don't owe..." thought process that leads to moral vapor lock.
I think there used to be more release valves for this pressure. There aren't any tithing billionaires, for example.