The onus is not on me to make this project's documentation presentable: it is on the author. My language skills are immaterial! The author's language skills do not excuse lazy presentation, they only help explain it.

They are material when you say that the author is being lazy for not writing English better or finding someone to contribute. It implies you don't know the difficulty of what you're asking, so why are you calling him lazy?

But of course you want to make it clear that you feel no obligation to contribute despite your criticism. So it's lazy for him, but not for you?

The grammatical errors exist regardless of whether I speak one, three, or a hundred languages fluently. Better to ask the number of projects I have documented...

Note I comment exclusively on the author's presentation, not thrir personal behavior: obviously they are not lazy. I have no obligation to contribute, no: ncome from or personal interest in this project. I contribute to the projects which benefit me and people who I care about.