James Landay raised the right idea – it is time for systems people in the CHI community to take control of UIST. That conference was setup in the 1980’s because systems papers were being excluded from CHI. So, rather than complain, I think a half dozen senior people in CHI community should get themselves on the UIST program committee, including the Chair. Then, make the conference you want it to be.
James, you might be the best choice for PC Chair.