I think a better title for this post would be, “How Far Should We Lower The Bar?”
Or, to put it another way, how many ignorant/lazy/stupid users do you want on your website? Seriously, how difficult is it to look 100 pixels to the right (formatting help) to prevent yourself from looking like a dumbass? How difficult is it to look 100 pixels lower (preview) to prevent yourself from looking like a dumbass?
And who browses with JavaScript turned off anyway? It’s like buying an ATI 5870 and then playing all your games at minimum resolution and minimum detail. If you have a problem with JavaScript, you have a problem with the Internet, in which case I suggest you GTFO.
“How do we treat user myopia? How do we reach these users?”
By irritating them until they either stop being lazy and learn to read, or get so irritated that they leave us alone. It’s a win-win situation; either you reach those users, or they sod off and waste some other community’s time.
Ignorance/stupidity/laziness should be punished, not be rewarded by lowering the bar to make it easier for people to act like that.
“I have used stack overflow for some time, and have only recently become aware of markdown. I thought I HAD to use HTML tags to get line breaks.”
If you can’t read simple instructions - that appear every time you post a question, and that are one click away on any page - I have to question your competence as a programmer.