Earlier (i.e. when I was a teenager), the most common or important reasons to write were:
- Academic: Exams, notes, reports
- Official: applications, memos, forms, files etc.
- Personal letters, letters to newspapers
- Creative and professional writing (fiction and non-fiction)
- SMS texts
- Social media posts and comments (blogs, tweets, comments etc.)
- Online forums
If my thesis is right, then it may explain why so many people publicly use "modern" spellings (i.e. sms-ese) even on channels that don't call for it. So you have people going "u hv ppl gng" even on Facebook when you might expect only a tweet or an sms to undergo that treatment. Two factors seem to be at play here:
1. A common observation in computational linguistics is Zipf's Law which says that if you order words by their frequency (in any reasonably sized collection of documents), and plot a graph of its rank against its frequencey, you'll see a graph like the one on the right (taken from here). The first few words (the top seeds) have the most frequencies, and this rapidly dies out to give a long tailed distribution.
Many words in language (let's exclude "function words" like "the", "of" etc.) are "homonyms" i.e. they are used to represent more than one concept (e.g. "fan", which could be an instrument providing artificial breeze, or a supporter). There are words like "set" and "run" whose different meanings are estimated to run into the hundreds.
The explanation for Zipf's law is (I don't know if this has been scientifically proven) that since speakers want to conserve energy, they want to use smaller words and want to reuse words (listeners would prefer the opposite: they'd want to hear unambiguous words).
The point of discussing this is that people are inherently energy conscious (read lazy) and would want to reduce the amount of work that they have to put in to create something. So writers would prefer smaller codes (i.e. shorter spellings) and let the reader figure out what they meant to say 1. You may have encountered the meme about how you could leave out (usually vowels) or jumble a lot of characters in a word or sentence and people would still figure out what you meant (works for "rspnsblty"; also see this post). So in many cases, a energy-conservant writer would be able to use this to his advntg (notice that I can't leave out "a" in that word).
With time, trial and error, and some form of community editing would leave us with a new set of acceptable lexemes (i.e. word forms) which seem to also have the desirable property of annoying older sections of literate society.
I believe spellings are arbitrary conventions, and there's nothing particularly sacrosanct about one specific code set. But that doesn't mean that "as u lyk it" wouldn't irritate the hell out of me, just as I'm sure Geoffrey Chaucer would find it hard to navigate the English spellings I take to be correct.
2. So far, I've conjectured that casual, off-hand writing has increased and that writers inherently prefer to expend as little energy in accomplishing their task as possible. There is one more factor at play: the permissiveness of the readers.
We are taught (correct) writing at school and we were expected to keep that up when we wrote for official or public purposes. We would get a clip in the ear for writing "Delhi wz da capital of India" (indeed, it would not even occur to us to write that way), and people would snigger if office memos or personal letters went that way. They probably still would. However, the modern increase in casual writing, where correspondents want to primarily exchange information without regards to form, it is incredibly easy to write shorthand and get away with it. Older fogeys may insist that anything you write to them be less insulting, but most people who cared about their spellings would just gnash their teeth in private and think of you as a whippersnapper of no merit.
This lack of censorship freely allows these forms of spelling to spread in the community unhindered. Soon, this spills over to other, more formal mediums as well.
In fact, I'm convinced that lexicographically, we are in the middle of a great and visible shift (I don't know if it qualifies to be a "Great Shift"). Usually, such changes happen over a large period of time, and aren't readily apparent. In this case, it is exploding under our noses.
What is worrying though is that in addition to a (somewhat) logical compression of a word ("you" -> "u", "people" -> "ppl"), young writers indiscriminately drop characters. I see "awsome". I see "wats need of raincoat,enjoy d rain". And I see "rememeber u ask me to to bring the...". There isn't enough 'sic'-ness in the world to cover this ailment. Is there an excuse for lack of attention to your writing?2
We as readers now encounter more text than we did before, which means some of us spend a lot more energy in comprehension than we used to. Do we now appreciate good writing more than ever? Should we be grateful that perhaps a Zipfian Law of appreciation has now kicked in?
1. I realise this argument fails if you ask why do writers ramble on, instead of choosing to write smaller texts? I'd argue that here ((just like in not paying attention to your spellings), the energy saved is in not having to edit. It takes effort to be succinct and so the rambling approach suits a "stream of consciousness" approach. Result: the reader is left to navigate endless verbal meanderings. I'll take the hint and stop here.