It depends on what your quiche dish is made from. If it is Aluminium, you can probably get away without blind baking as the heat conductivity is so good.
Non-stick coated or tinned steel dishes are a bit touch and go, depending on the mix you are putting in the quiche.
Ceramic dishes are usually not good conductors and it is nicer to have a fully cooked (and crisp, ideally) pastry layer than a half cooked spongey pastry flannel. Better safe than sorry, I would blind bake.