Piling on re: mixing roles: I read "abuse of position" in the GP comment as "conflict of interest," which is potentially problematic for a board member of a non-profit.

I can't speak to the veracity of the facts presented in WP Engine's C&D letter, but my reading of it is they're accusing the head of the WordPress Foundation, in his official capacity, of putting the interests of his for-profit company ahead of the non-profit's stated mission. That's the sort of thing that could threaten the foundation's 501(c)3 status, or in extreme cases lead to criminal charges.