Is it really that hard to write well? I find it much simpler than trying to use slangy "netspeak."

It may not be strictly required by forum rules that you follow correct writing procedure, but you will never be taken seriously if you cannot even muster readable, serious writing. See Dr. LaVey's humorous essay "Writter's Block".
"The devil I'll bring you," answered Hagen. "I have enough to carry with my shield and breastplate; my helm is bright, the sword is in my hand, therefore I bring you naught."