I think you may have misunderstood my emphasis (my fault). I'm not interested in the grammatical mistakes as such; I'm interested in what happens when I go to read a web page from a source I'm unfamiliar with. Because URLs are pointers, I jump directly to content in medias res with very little context. In the absence of context, other indicators fill the vacuum. In this case, the sloppiness of the writing affected my perception of the author - which may be unfair. I'd have to read more to know for sure. But that's my point: fair or unfair, I'm not inclined to. (The photo didn't help, either.)

It's interesting that you brought up not being a native speaker. That is a piece of context I instinctively scan for, because if I get it wrong my judgment will be off. In this case, the title ("a UK VC") and the fellow's name made me expect the Queen's English and, now that I think of it, probably raised the standard I unconsciously applied.

One can make errors about this. I knew an American who had mastered Russian to such an extent that Russians thought he was Russian. This backfired. Inevitably, he would put things in a way that a real Russian never would. Not realizing he was a brilliant student of their language, native speakers concluded that he was an illiterate Russian. That's something Russians care about a lot, so he got badly treated.

As for your comments, I don't ignore them; I'm familiar enough with your user name that I must have read many of them, though I don't remember anything specific. I bet that if I had been asked, I would have identified you as an intelligent non-native-English speaker, and if I noticed any spelling mistakes I doubt they mattered.