I agree with post 7 that shortcuts are a natural adaptation of language. I think where we get offended is when shortcuts are used even though they are not necessary. In conversation, I would much rather hear "that's so funny" than "lol." In a text message, it doesn't bother me but in conversation or formal writing I really hate it. Sometimes I think our shortcuts strip the personal touches away from our communication and our relationships.
I agree with #6 - while it is easy to blame texting, there are many examples of shortening that predate modern electronic communication. For example, the military uses all sorts of abbreviations and shortcuts, both written and verbal. One thing that may help create our propensity for shortcuts is that fact that we can think faster than we can talk, and much faster than we can type, write, or text. Shortcuts are a tool to help the mode of communication keep pace with the thought process behind it.
We have always abbreviated words when we have become comfortable with their usage. We rarely say perambulator, television, aeroplane or even telephone nowadays - we talk of prams, TV's, planes and phones. The village next to mine in Bolton, UK (there's another one!) was called Hallithwood, written Hall'i'th'wood and meaning Hall in the Wood. Texting has merely highlighted this phenomenon.
I understand why some people view it as evidence of the decline of writing skills in our society, but I think it is simply an adaptation to technology, one that I don't view as something to be resisted, as the first response says. I do think, however, that we need to be careful to emphasize context when we are writing. It is entirely appropriate to include abbreviations and text slang in conversations with one's friends. The reality is that doing so in a cover letter for a job, or a term paper in a class, will probably not go over quite so well.
I agree that the shorthand started with texting on traditional cell phones. It made (or for those of use who still have phones without a keyboard makes!) it quicker and easier. In additional there was a time when texts were charged by size rather than by message or unlimited plans. The less characters you used the cheaper. As time has gone on, it has just become habit and is still easier and quicker. However, I do think that laziness plays a part in it, because while shorthand is acceptable in some situations, it is totally inappropriate in others. If you were to use text shorthand in an assignment turned in my class, you would lose credit. If you were to use text shorthand in an email to me (not personal, but student-teache or professional) I would be offended and with students expect it to be rewritten in a more formal way, because the relationship is formal. I also agree with the post that says that language changes over time making shorthand just a new form of slang. However as has always been the case there are times, places, and relationships in which slang or informal language is ok, and there are times, places, and relationships where formal language is necessary.
I think it goes back to the roots of text messaging. It may be hard to understand today when most people basically have a minature keyboard at their disposal to type away. When texting first surfaced, however, there was only the number keys to use and you had to press them a varied amount of times to scroll through the possible letters for that number. Obviously this wasn't a quick process, so the "short hand" of texting developed.
I do not see anything wrong with this, really. Language is not something that is meant to stay some certain way forever. There is not some form of the language that is morally better than another. The kind of shorthand that you are talking about is simply more convenient than typing things out in full would be given the medium of "text." It's natural, not something that needs to be resisted.