I agree with the initial point made - shorthand in forums is annoying.
In game's a different matter, of course, as I'm sure lots of us have had to end up typing "Argh, I died - blasted chat" or something similar, when we spent too long typing to friends. So the short words do help.
But in the forum, do you have the same problem? I mean, if you have a dog in your room that tries to bite your leg off if you type for too long at a time, then I'll be happy to send the people from the pound around. Oh yeah, I'll forgive abbreviations too.
One plus point about using the correct words is that non-native english speakers have more of a chance. Why confuse them more than our language does anyway?
Really, there is no reasonable excuse for it. To those that say the new l33t-spk (or whatever it is classed as) is due to text messaging, and think that is a good enough reason to use it with a qwerty keyboard, need I remind you that most phones nowadays have predictive text, which means the correct spelling is just as quick and easy.
Oh, and people used to need shorthand in telegrams, but it wasn't used as an excuse to forget how to spell.
Use your shorthand if you must. But don't blame me if you get treated like an ignorant little kid.