There's nothing strange about how often this error is repeated. It is a fault in the "design" of the English language, which violates its own rules, insofar as it has any. Apostrophes are used for both possessives and contractions, eg. "That's John's ball". Indeed possessive "it's" was historically written with the apostrophe. That the apostrophe was dropped to become possessive "its" is completely arbitrary special-case logic, and given that there is no logic behind which it was dropped from, it is easily subject to confusion because you cannot reason about which is which if you forget in the moment.
"its" is precisely parallel to "hers" though?
Indeed, it's pretty much the opposite of "logic and precision"
I really don't think it's an issue with how the language is structured. I think it's more an issue of posters using mobile devices and not spending a lot of time copyediting their comments. It surprises me how many users on here shamelessly post mobile-subdomain links, rather than the desktop ones that only redirect to mobile if you're on a phone.
Thanks for your response. You raise an interesting point, but I take a different view. Contractions _always_ use an apostrophe, while possessives only sometimes do [they're / their, you're / your, he's / his, she's / her, it's / its, ...]. For "it", the apostrophe alone serves to distinguish between the two words.