This is illuminating. Most of the time, those who read text that exhibits bad grammar or ambiguities and discern the intended meaning by the context. So, if the message was between two people who had arranged a ritual cannibalistic meal where they ingest the remains of their newly departed, then both parties would know that the meaning is an invitation to eat Grandma's remains.
I am all for good grammar and spelling, but the internet has made common new forms of interaction in the form of text messages. emails and postings like these. Each type of communication is evolving its own set of rules. Older forms of communication such as private speech, public speaking, phone conversations and letters also have a set of rules. We tolerate a lot of error, bad grammar and ambiguity in private conversation because the effort it takes to properly formulate conversation would destroy the immediacy of conversation. Listen to conversations sometime and observe the errors, the "uhs", the "you-knows", and incomplete sentences. Some conversations are nearly incomprehensible to any but the participants who have the advantage of context and shared experience to resolve ambiguities. Formal written letters or public speeches are held to a much higher standard. More people will receive these communications, so accurate grammar and language is important. But these forms of communication are less immediate and less personal. More effort is put into these more formal forms of communication.
The new forms of communication seem to me to fall between the lax standards of private speech and the strict formal standards of formal letter writing or published articles. For example I find that most text messages are normally intended to be quick and informal forms of communication. Various abbreviations (like "k" for Okay) are created to facilitate fast low-effort communication, and poor grammar in this setting is tolerated in exchange for the low level of effort to facilitate the speed and convenience of texting. Internet postings and emails require a higher standard that texting, but these also are intended to be created and viewed and discarded relatively quickly. (This post for example, won't be read much because I am posting in the afternoon from the west coast of the USA after 600+ other comments have been posted. This entry and all of the comments are already history for most /. readers.) As such they are not normally held to the same standard as we would expect from more formal forms of communication. The one exception is the rhetorical flaming of the grammar in order to score rhetorical points against someone with whom you disagree.
So, while I think we should always encourage good writing and grammar, I think less rigid standards are acceptable in some of these newer modes of communication depending on the need for immediacy instead of accuracy.