That's your e-readers fault for implementing PRE as if it were a web browser, and then leaving out the horizontal scroll bar that made PRE issues recoverable :-P.
I think it would be nice to have extra CSS properties which could be applied to change PRE to use hanging indents. AFAIK you can re-enable line-breaking, but you can't set an indent. That would let wrappable poetry use PRE, rather than putting each line inside it's own <P> tag (with custom styles), which can work well but is a bit of a hack.