To protect yourself. Nothing beats a drone better than another drone. Also, when fighting back versus a drone it's good to know the basics.

Right now you can buy guns, and the govenment can buy guns. It's on 1 on 1. The government is investing shitloads of money in drones, they already have their drones and they will have access to even more advanced drones in the near future, you think you will be able to buy a fighter drone? Hell no. That's why should learn how to create one yourself.