Agreed this is a problem, I recently posted about this as well. The whole jury of our peers concept, which is extremely important BTW, goes out the window when you try people in places like SF, NYC, DC.
They are such radically extreme concentrations of people and bizarre places on the whole, that 99.9% of America would never visit and has no interest in or relating ability to.
Random sampling doesn't matter much when your population is such an extreme concentration ...
Definitely a weapon, these DC and NYC prosecutors who just go and charge any national figure (all of whom of course have some doing-business in DC or NYC as a matter of course), knowing they'll have a jury full of crazies.