I might not go as far as "very rude", but I basically agree. I don't find corrections like these useful, and I doubt I would even if I was the one writing in a second language and being corrected, except when my errors were genuinely obscuring my meaning. One serious comment about what I am saying is worth any number of such trifles.

I guess that Dmytry's native language is Russian, which does not have a definite article, and so it is unsurprising if he sometimes uses "the" inaccurately. But having sussed that immediately on seeing his name and the first three words, it's of no further importance. I'm not here to give or to receive language lessons.