I doubt it is the lack of time. But natively English-speaking acquaintance to proof-read technical documentation can be very hard to come by. Most projects have to do by with the folks they have. ( I am in need for such a person myself. If anyone has the time Searchdaimon ( https://github.com/searchdaimon/enterprise-search ) could need some help :) )
One trick can be to at least wikify the documentation so other can easier pitch in.
Instead of bashing someone on hnews comments, you could send them an errata patch.
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?
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.
The author's primary (and perhaps only) contact with users is through their documentation. Incorrect capitalization and apostrophe use is distracting and will put off some potential users. The author looks sloppy and uncaring because these types of mistakes are preventable.
Being a non-native speaker is not an excuse for basic errors (excepting novices). Proof-read your docs! If you're not confident in your language skills, ask someone else to!