Sometimes their patches aren't even valid - they tried to fix "borken" to "broken" and the maintainer was not happy: https://lore.kernel.org/lkml/YK3wOkX6I78j73zD@gmail.com/ (this does come down to not being familiar with this particular bit of slang - but they push back and argue a bit which doesn't help)
Sometimes the maintainers are not happy just getting a patch that fixes one line of whitespace: https://lore.kernel.org/lkml/20210608105943.2376328c@oasis.l...