I pretty much agree with you. I can take netspeak or whatever that's called in chatrooms, MSN etc. but if I see someone constantly using it (even lol) on forums or, dear Lord, essays or stories, my first impression of that person won't be very positive. Even if they actually have something intelligent to say, I will be too busy frowning at their use of language to notice.
I take language very seriously in general, and netspeak is just the tip of the iceberg for me. I am disgusted by how people think it's apparently okay to abandon grammar, punctuation, and common sense just "cuz its just teh internetz, lol!!!!"
Another reason I dislike netspeak is that I can't read it. I had no idea what "ttyl" was before this post and I've been entirely ignorant about that "WTFBBQ" thing I see everywhere.
What the heck is that anyway?