That's one opinion. It is, however, not exactly in harmony with the general and best practices of the trade.

The practical problem with the general recommendation to grease tapers is that everyone has grease sitting around, but relatively few people have torque wrenches. So tapers get greased but not torqued to a value. And greased tapers make overtightening much more easy, so you end up with the OP's result.

Most manufacturer spec is to use a dry spindle. The major bicycle mechanic's institutes also recommend dry installation. So does the JIS manual: "Affirm that there is no adhesion of foreign matters and the like at the inner wall of corner hole of right crank and right corner face part of bracket axle..." JIS recommended torque is 30 Nm.

I disagree strongly with the general recommendation to grease spindle tapers because of the above, and for other reasons I won't go into depth on here, because they have been elsewhere discussed to death. Suffice it to say that torque values given by manufacturers are always for dry bolts and tapers unless specifically noted otherwise. Greasing either or both requires the torque to be decreased by as much as 25%.

I DO agree strongly with Brandt's recommendation that correct torque is far more important than whether the spindle is dry or greased. If you have a torque wrench, feel free to use a tiny amount of lube if you want. But take into account the effect that has on the torque value you should apply to the bolt. I also agree with him that too much torque will not crack your crankarm unless it has been done repeatedly, causing the bore to become oversized. (Which, may I point out, is not exactly in harmony with his recommendation to grease the taper, which increases the chance of overtightening even when using a torque wrench.)