For me the historical text argument has little value. Communicating with each other in the present to me is much more important than being able to read or decipher writings from the past.
I do agree with Patricio that the most important thing is to be able to understand each other, without worrying about the details. But as NStride mentioned, your writing tells something about who you are. Apart from things like dyslexia, consistently making the same 'mistakes' may give others the impression that you are someone:
- who speaks before thinking about what to say and how to say it.
- who is more concerned about expressing himself, than reaching others.
- who isn't willing to learn or correct/change himself.
I'm not saying this is necessarily true, but it can definitely be interpreted by others this way. Of course you can be aware of this and just not care about it (wanting to make a statement, not looking to reach these particular people, etc.). But if you're not aware of this, you might be too self-involved to notice how you come across to others in the first place.
A more detailed remark, which may be something personal (or not):
Patricio wrote on 04/18/11 at 18:42:54:And who honestly cares about where you put commas and shit? why does this matter?
I do! It doesn't have to be a perfect use of commas, but reading long sentences without them is a true pain

Punctuation gives the reader to chance to breathe once in a while.