I think walls of text are matter of time and place. My recollection is that Paine, Jefferson, and Franklin wrote in very long paragraphs, with very long sentences in them.

For contemporary texts written for the web, I'd generally agree, and even if I don't think the writer is a crackpot, I'll stop reading because of the difficulty of visually tracking through a wall of text.

I can't say I have. But I would't judge a text based on some peculiar font use, either.

You have to read and understand why it is good or why it isn't. Shortcuts like "funny grammar" are not reliable.