Only if the writer requests it, otherwise it's just rude.
Typos and spelling mistakes could be laziness or it could be that English is not the first language of the author so a degree of tolerance is called for, not everybody who wants to be heard has a degree in English language but that shouldn’t mean they remain silent.
If someone is deliberately promoting disinformation then we can try and judge the reason why, it could be harmless delusion so why bother. On the other hand if it is more serious then we can flag it and bring it to HP's attention. Some people deliberately try to start arguments to obtain attention or acquire an audience .
However most Hubs are started for a reason and usually comments are invited, and of course if your opinion differs from that of the writer you are quite at liberty to say so, although it should be done in a reasonable manner with resorting to abuse or rudeness. We can all agree to disagree over all sorts of issues without becoming mortal enemies.