I agree with you. It's not normal, but it is annoying. People may not be lazy or stupid from abbreviating words, but it does make them come off that way because it is the common jargon of tweens. I hope that when I'm 25 I have more common sense than to use "nd" to substitude "and" when I'm talking to someone. Why would you want people to think lowly of your intelligence when you're better than that?
Why would you want people to think lowly of your intelligence when you're better than that?