I guess my reply might have been ambiguous. Systems professors are generally especially pragmatic, mainly because of the maturity of the field and their culture (reflected in the high standards for top tier OSDI/SOSP papers). Mobisys and Mobicom are becoming more of a venue for the sensing community, which is relatively new and still dealing with technology that is a few years from being ready, so it makes sense that they are more on the interesting side. For systems work to be interesting, they go off and show how it can pragmatically improve your life (e.g., by finding lots of bugs in Linux).

I'm not a systems researcher but I work in a systems research group (at MSRA) as a PL researcher, which is a very different community; we tend to be more designy.