[jruderman]

about:memory is primarily intended as a debugging tool, so we can diagnose and fix memory problems. It has been a fantastic success in this regard.

It also gives add-on authors and web application developers a chance to do the same.

If some (advanced/heavy) users are also able to use about:memory to diagnose and work around problems they encounter, that's a nice side effect. As long as some of those users remember to file bug reports, that is :)