While I do agree there isn't any hard data supporting the notion Elon's tweets (X's?) negatively impact Tesla, I also feel it's realistic to make the connection they have had some noticeable negative impact on the brand. I know a few people personally who have changed their tune about Elon and Tesla in the past year based on his posts combined with the FUD distorting them. And while it's likely the media has turned his tweets into a larger impact than they deserved, nevertheless the impact is tangible, because I see many people on other forums and social media claiming they will not buy a Tesla because of Elon's behavior.
To claim it isn't a real thing would be disingenuous. The debate on how small or large this impact is very undefined and worth discussing IMHO, but that does not make it non-existent. There has been an impact.
I think for HODL'ers the impact is negligible in the long term, the companies products, services, and revenues will negate any downside from Elon's posts. In the short term the impact could be important for TSLA and Tesla.