It's frustrating because it's extremely difficult to read. This is a message board and as such writing is our only form of communication. That means you need to make some effort to be understood. If you really are uneducated, fine. If English isn't your first language, great. But I know many people online who have English as their 2nd and even 3rd language and they use better grammar and punctuation than many (supposed) native English speakers on this site.
[Please note I have infinite patience for those who are not native English speakers and have trouble with English... they're exempt from my ire on this subject as are people with learning disabilities related to reading, receptive language, and expressive language.]
The indifference and disregard are disrespectful. We're all on media that enable us to write legibly. We even have tools to help us with grammar, punctuation, and spelling. Use Firefox, for crying out loud. It has a built in "English teacher" to highlight spelling mistakes. For people using iTech, I know those have software to help too. Autocorrect is a helpful tool. Use it.
I grew up with an English teacher who was also a secretarial teacher for a mom. I have no excuse. I make typos and little brain farts but I make my best effort not to, and that includes refraining from using obscene amounts of abbreviations out of courtesy for the posters who aren't fluent in English abbreviations and/or are new to posting in online communities and don't know the jargon.
What worse to me than grammar mistakes and misspellings is posts loaded with text speak.
I'm not saying a post has to be grammatically perfect. Not at all. Just please recognize that your audience isn't 2nd graders.