Most native English speakers tend to take blunt statements/questions negatively due to the culture (especially true in north America).

I enjoyed reading the article but I would agree with the above commenter that it may be a bit lengthy. Generally speaking writing tends to be more engaging in this format if it's a bit more concise, both as a whole and on a per sentence basis.
There was also a typo somewhere, I think "the" instead of another word, I read the article a few hours ago now so I can't remember, sorry. I don't think I would have guessed you were not a native English speaker from the article. Overall, I liked it and congratulations on putting something out there!

I feel bad for you OP, I get this a lot and I'm totally gonna go there because I feel your pain and your article was fantastic! I read almost every word ;p

This phenomena stems from an aversion to high-confidence people who make highly logical arguments from low self-confidence people who basically make themselves feel unworthy/inadequate when justly critiqued/busted. It makes sense for them to feel that way too, I empathize. It's hard to overcome the vapid rewarding and inflation in school. They should feel cheated and indolent at this whole situation.

I'll be honest in front of the internet; people (in majority mind you, say 70-80% of Americans, I'm American) do not read every word of the article with full attention because of ever present and prevelant distractions, attention deficit, and motivation. They skip sentences or even paragraphs of things they are expecting they already know, apply bias before the conclusion, do not suspend their own perspective to understand yours for only a brief time, and come from a skeptical position no matter if they agreed with it or not!

In general, people also want to feel they have some valid perspective "truth" (as it's all relative to them...) of their own to add and they want to be validated and acknowledged for it, as in school.

Guess what though, Corporations, Schools, Market Analysis, Novelists, PR people, Video Game Makers, Communications Managers and Small and Medium Business already know this! They even take a much more, ehh, progressive? approach about it, let's say. That is, to really not let them speak/feedback, at all. Nearly all comment sections are gone from websites, comment boxes are gone from retail shops, customer service is a bot, technical writers make videos now to go over what they just wrote, Newspapers write for 4th graders, etc., etc.

Nothing you said is even remotely condescending and nothing you said was out of order. Don't defend yourself in these situations because it's just encouragement for them to do it again. Don't take it personally yourself, that is just the state of things.

Improvise, Adapt, Re-engineer, Re-deploy, Overcome, repeat until done.