It's not disproportionate. I've seen this time and time again; some people _can't help themselves_ being conflictive and reraising certain issues.
You either put a sock on it and move or you allow this discussion to go on forever.
And yes, as the owners and founders they are entirely within their rights to run the company as such. It hurts some people to remember that companies aren't committees where everyone's word matters the same. That's just the way it is.
If the response to that situation was to have a discussion with that employee / group of employees about the need to move on and come to a resolution, instead of blasting publicly that politics and committees, and basically everything other than DHH and Jason having absolute authority is no longer accepted, we wouldn't be having this conversation in the first place.