Musk's argument is that we know for certain that the
entire road system can be navigated by visual cues
We know for certain that human brains can be assembled out of regular atoms, but raising funds for a company that manufactures brains would be getting rather ahead of our current level of technology. The same might be true of computer vision and autonomous vehicles.
HN has never been mobile friendly, (element spacing, upvote button size) so I'm not terribly worried about that. If YC wanted HN to work on phones, they would fix their CSS.
Block quoting can screw up desktop rendering on HN if the quoted line is too long. Say you put a 1000 character line in a literal quote:
1.......1000
The whole page would render at the length of that line. So this text that I'm writing now, it'd normally wrap once or twice depending on your window's width. Instead, it'll only wrap after approximately 1000 characters. This is why when I block quote, I put in a line break every 60-70 characters (similar to what you did a few posts up).
I know this behavior happens with IE, I believe I've seen it in other desktop browsers but can't verify at the moment.
On desktop long block quotes go in a scrolling box. One that's pretty wide, so it doesn't usually cause a hassle to have to scroll it. But not so wide it breaks anything.
Additionally to what Jtsummers said, quoting on desktop can drastically reduce the line length compared to the rest of the lines in the comment, which is both ugly and annoying, especially since it makes it more difficult to read since your eyes are whipping back and forth.
There are a multitude of mobile apps for consumption of HN, most of which solve the code-block-line-overflow problem by adding a horizontal scroll, which only makes the problem worse by forcing users to scroll side to side to read the full quote.
Just use `>` at the start of the line to signify that it's a quote, please.
