I have to disagree. If you fire so highly pejorative a word as "bigotry" at another commenter, that's crossing into personal attack, and you can't undo it with qualifiers like "almost" and "borders on". The pejorative burns through.

The fact that the OP was actually talking about Esperanto, of all things, shows how off-base that was.

I'm sure you didn't intend your comment personally, but I'm equally sure that the OP wasn't intending anything nefarious. Pouncing on their use of a single word "ethnic" is just the sort of thing that guideline I quoted asks commenters not to do. If you had paused before pouncing, you could have come up with several other things they might have meant.