I don't find "walls of text" at all forbidding, as long as the line width isn't ...

I don't find "walls of text" at all forbidding, as long as the line width isn't too long. I also find Joel's argument on this point a bit dubious:

When was the last time you noticed a popular magazine or newspaper with entire pages of text?

True, but books do it all the time---as does Joel's essay, except for the gratuitous pull quote in the very section under discussion.