Actually no. And this comes straight from Richard McLish. If you combine 5 or 6 piezos in parallel the impedance changes and it can be used passively. I have a piccolo with a magnetic and a bridge full of piezos and I use a blend just like it was 2 magnetic pickups.Piezo require a pre amp to yield a useful signal. That's why they are less common.
I think one reason people hate piezos is they are often placed under the saddle. If magnetic pickups were only placed right up against the bridge and no where else they would have similar tone issues.

