Comment by ianferrel
Rigid whiskers have other sets of problems. Below someone mentioned that rigid whiskers will break when they contact objects. If the whisker is as rigid as the drone itself, it plausibly breaks the same cables that the drone breaks. You also have the problem that in the event of drone failure, you now have a spike-covered drone falling out of the sky. What kind of damage does a bamboo chopstick or thin piece of steel do when it hits someone or something at ground level at drone-falling velocity with the mass of a drone behind it?
It's quite possible that these problems are solvable and can be engineered around, that there's a whisker-based solution, but I don't see it. It's certainly not an obviously workable solution.