I'm not sure if it's an age thing, I see about as many older men on Fetlife use really informal and short text speak as younger guys.
Some old people act like children when you let them on to the playground. I'm 76, and I tend to be fairly casual when writing to or about dommes here (and I've been accused of being disrespectful, too), but if I'm exchanging private e-mail, I'm on my best behavior.