Whatever gender-neutral language may usually be like, in this case I don't think the correction to 'person' is very stilted or distracting, IMO. (Would be even better to replace 'he or she or it' with 'they', but I realize some people dislike this style.) There were also other possible modifications to the text.

Assuming you agree (since you changed your post) - part of the problem is that even in a case where a good solution was relatively easily available, you didn't look for it, even though you knew your phrasing might be offensive to some readers (or distracting or whatever you choose to call it). This implies, to those readers who are distracted by your phrasing and spend a few seconds thinking about the issue, that you didn't bother not to give offense. And that's what (some of them may be) really offended at, I think. Continuing this, your comment implies that any reader who takes offense is behaving "unintelligently".

While you say,

I decided to write it from one gender's point of view, and trust the reader to interpret it intelligently.

What you mean is, you trust readers of the "wrong" gender to interpret. Readers who are "like you" in this aspect, which ought to be completely irrelevant to the discussion at hand, don't need to interpret anything at all. And gender-biased text distracts the "wrong" readers a lot more than most gender-neutral text distracts you or most other readers.

While "intelligently" means here "whatever I meant even if the text I write doesn't express it well". I wish this kind of communication worked. But it doesn't. When people repeatedly tell you that some not-quite-literal turn of phrase you're using is misinterpreted compared to what you mean, I think you should stop using it.