If you read it out, and it sounds the same, then I can not get worked up about the spelling. Bear/bare, your/you're.. etc.
It is being pedantic for the sake of it. You know what the poster is trying to say. MN is not an academic essay.
It isn't always clear. Why do you think language evolved with so many variations of spellings for homophonic words meaning different things, if only the sound of the word is important in conveying meaning (in the absence of aural tone and context)?
I get that there's a huge spectrum between the stereotypical caveman pointing at everything he sees and saying "Ug, ug" and a paragraph of beautiful, grammatically-perfect prose, but why draw the acceptable balance bar so low?
In most human endeavours, we toil endlessly to improve continually - be it an athlete wanting to shave a hundredth of a second off their time or the most minor little comfort or safety tweaks in cars - why do we care so little when it comes to language?
I don't buy the insistence that "It's only an internet forum, why does it matter?" Why doesn't it matter if you not only struggle to communicate properly with others across the world using the modern world's main communication method, but you actually don't care if you can't? Why would you deliberately choose to be held back, if you didn't need to?
There are many millions of people across the world now who speak English as a second, third, fourth, fifth language, to a much higher standard than a great many native/monoglot English speakers do - and are apparently content for that to remain the case, even down to just not bothering to click on the red line that prompts you of a mistake and gives you the correction. I really struggle to understand why.