Connotation is more difficult on the internet. Sarcasm likewise. Body language, tone of voice, and other nonverbal cues let you convey subtext in person that is difficult to reproduce on a computer.
It should not surprise you that people look for other means of reproducing these effects.
Personally, I find artfully butchered grammar sublime.
(Particularly if the person employing the butcher's knife has established a reputation for knowing how to use grammar correctly. It's almost counter-intuitive: by establishing consistent writing methods, you gain credibility when you deviate from those methods. Otherwise you just seem to be stylistically flailing--for example, look at people like Classic, or me.)
(alternately, you could always do it intentionally wrong in the same, specific way. i respect that approach as well.)Bottom line: breaking the rules of conventionality will always be a useful tool in the communicator's arsenal. Understand that by doing so, you increase your potential range of expression while alienating a portion of your audience. I find that is a reasonable trade-off; if someone reading me dismisses my words just because I happened to use a sentence-form she disliked, I'm probably not that interested in getting through to her, anyway.
To address the original topic, however, the important thing is knowing at what point you're alienating so many people that you might as well not be posting in the first place. Tiny text has crossed that line, for this community. I'd suggest that emoticon-strings are getting close.
