While I don't agree with everything he puts out, I agree with Jobst Brandt on this one. Grease the tapers.
I have always done so and never had a problem. Anything that gets torqued needs to be greased to get a proper seating and torque measurement.

Crank arms that come into the shop stuck are invariably not greased. This alone says "grease the tapers".

This is certainly a religious issue, and, as previously pointed out, a can of worms has been openned (again).
Drink the Kool-Aid of whoever you like and grease, or not grease, accordingly.