I get that this is a small insular community and the mute tool, as it is currently implemented is important for maintaining that and you're "100% entitled to be the arbiter of that decision." You are, after all, the most popular guy here. Nevertheless, I don't think he needs to apologize for being a little hot under the collar. I'm sure you've been hot under the collar as well and nobody expects you to apologize to some plebe who mutes you. I think he makes a valid point:

Keep in mind, Klein is a major user, and this will thus remove a decently sized portion of the site from my ability to communicate. Was this likely a place I'd communicate with anyway? Perhaps not, as I did not follow Klein. However, the effects are unequal, as being a small user, Klein will likely never see any content I push anyway, and thus can mute me without fear of losing the ability to discuss openly.

I don't see his discussion as being inherently "dishonest," and perhaps that is the heart of our disagreement; he may make flippant remarks, but who doesn't do that from time to time?