Heaven forbid Tesla engineers decide to feed the homeless during their work hours at the CEOs directive. That's not servicing the publically traded company.
Except that’s not what they’re doing, so I’ve no idea why you think that a relevant argument. They’re working for a different public company while being paid by Telsa.
> They’re working for a different public company while being paid by Telsa.
Actually, it's worse than that. They're working for a different, private company, one which happens to be owned by the CEO of TSLA, who has a legal and fiduciary duty to the TSLA shareholders.
Why would a TSLA shareholder make a fuss? It is likely that Tesla will bill Twitter for the use of staff resources. Other than that, being on good terms with the owner of Twitter is a possible advertising opportunity/tie-in in the future.
Your example generates company pr value, employee morale, etc. Meanwhile there is no value being generated to Tesla by moving these engineers to some side project for another company.