Some companies have board governance rules that mandate a majority of the board seats be of "outside and independent" individuals, but of course this can easily be gamed and, of course, these rules themselves can be put to a vote during shareholder meetings.

Still, it's always worth considering these structures before one invests--especially in med-to-large-cap public companies.

Alternatively, in private small-cap and venture-boards, the seats are nearly always filled by founders and lead investors and I would argue that's a "good thing".