I’ve made so many mistakes in grammar and punctuation in my own writing I wouldn’t dare comment on someone’s blog post, article or even a tweet. But that your/you’re thing on FB happens far too often to be a typo. I’ve seen it in memes. It makes me a little nuts.
So yes, correcting it won’t stop them and the satisfaction at trying would be fleeting at best. I think Microsoft, Apple and Android should make systems that autocorrect to you’re and 98% of the ‘yours’ would just, go away. If you don’t agree, your wrong.