I feel your pain OP - this makes me very twitchy. I often wonder why so many adults are oblivious to this - you’d think at some point they’d notice that their is not the same as they’re, just as 1 isn’t the same as 5.
I do notice it here but hey, it’s not my job to police the threads so I don’t comment. Besides which, we’ve all had different levels of education but I like to think we all bring something to the table in life.
I am very tolerant of spelling mistakes but get really judgmental about 'of' as in 'she should of checked her spelling' and sometimes I get so baffled by the wrong they're/their/there I have to say it out loud to get the meaning. I believe we have visited this theme many times.