This isn't an opinion/confidence issue, it is a legal one. If there is even one shareholder (i.e. anyone in the world with $228 to spare) who wants to push this issue, they can. Realistically it would take more than that to make it worth suing, but the point remains that even if 98% of shareholders think this is totally okay, it could still be a huge problem for them.

Additionally, there are various institutional shareholders that don't operate based on their personal opinion of Musk/Tesla, but have specific legal duties to protect their investment in the company.

The SEC could still act on the issue even if it was somehow proven than not a single shareholder actually cared.