That's interesting. I'd actually like to tweak the stylesheet too. Seems easy enough now you say it, but a post about doing that might fly well. (I'd quite like to hack Safari Reader to get rid of that full justification too, but I need to Google on how to crack into that..)

I guess I concur that it is annoying in most contexts, but hadn't noticed it here. Maybe it's a difference between browsing/skimming behavior and prolonged reading?

It doesn't seem to be so detested on devices like the iPad and iPhone. Page turning is a form of horizontal scrolling, after all. I haven't yet tried your system on the iPad but I think it might cut it for me.

I suspect the aversion to horizontal scrolling on the desktop is based on history and, then, habit. As you may remember, scrollwheels used to only go up/down so horizontal scrolling was cumbersome. You could also scroll by vertical page by pressing space or PgDn in most apps. Similar shortcuts for horizontal scrolling are/were rare and inconsistent. Vertical scrolling was so easy that, by comparison, horizontal scrolling was annoying and difficult.