It could be also because, we foreigners learn to write English prose through our reading comprehension, not via our listening circuitry. The text probably feels "normal" to me when I read it back to myself, but there's no "proper" feedback loop from the native speakers - I have zero idea how my written shit sounds to a native ear when they try to read it. I still do agree though, it feels so friggin' annoying these days to have to deliberately butcher some words and make sure there's a typo somehwere in your text, just to convince people that tis indeed a crap straight from my "head to the paper", not a slop.