Personally I dislike the deciphering option. Yes anyone can make a grammar or spelling mistake, especially if a language is not one's own. Just using any slang and internet lingo is also allowed but it makes reading and understanding the message a lot harder than any well-written comment.
Then there is my observation that _most_ bad-grammar comments have relatively shallow content. These things combined usually make me stop reading after a few words. If a person doesn't think his message is worth stating clearly then it is probably not worth the trouble of deciphering it.
Simply put, first impressions are important and grammar, spelling and good use of e.g. commas are part of that.
It matters to some, but obviously not others. What we see is the collision of two attitudes: If you're going to write something, do it right, versus "Just as long as it can be deciphered by the reader." I see no reason to write terribly, and I dislike when people don't make the effort. But that's my view, and I guess that of GalaxySpinner as well. In the end, language is what people make of it, so we each do our part to make it what we want it to be. And whenever people disagree, there is potential for argument. But argument isn't a bad thing, only hatred and illwill.
Ooh, once again Galaxyspinner, you're upsetting the vast majority of internet users. Let's not forget that in America today, we all accept everybody for who they are and don't put them down, no matter how poorly they write.
The biggest disappointment to me is that people graduate college without decent spelling and grammar, and the decline in literacy is starting to creep into every form of publication.