Imagine drawing apps that could only handle a fixed width, or spreadsheets where you could only go as far as the F column
That is true. It is also true that it is becoming more frustrating to use the web for its original purpose of reading plain text documents, and the need to scroll some pages horizontally is a symptom of that.
It's one of the many reasons post-Lion that I've decided to just move on to another OS. I shouldn't have to adapt the way I work to some OS updates quirks.
Since a trackpoint can't possibly support two-finger scroll, which is what makes scrolling both directions so easy on a trackpad, it seems like you either would need to drag the scrollbar block or hold down a key in order to scroll, two cumbersome solutions.
All browsers will not automatically wrap text inside pre tags, since the text inside pre is supposed to have both width and line-breaks preserved. Scroll with two fingers inside the box to view whatever has been hidden by "overflow: scroll;". If you find a site that lets pre code snippets overflow into the right sidebar and off the screen, let them know their site is unusable and to add an overflow CSS rule to make it respect smaller screen widths.