When planning a doomsday device, you need to balance cost, power, utility, and a few other factors. The whole process is taxing, mentally, but ultimately worth it. I recently went to the trouble of researching, pricing and purchasing a new "Big One", which I currently wait impatiently for. But I don't rage and curse every delay, I simply make more preparations with my extra time.
Or at least I DID make preparations. Now I sit, in a hospital, again, cut off from my usual tools and productivity devices, in danger of missing the delivery of my Doomsday Device. It's not like they're going to leave something so dangerous on a doorstep. That's where trusted henchmen come in.
Not those nameless minions so plentiful in number that it's not possible to tell them apart without a database of distinguishing features. One of them would drop it , accidentally trigger it, or screw up the settings before I get a chance to look at the Manual.
No, True henchmen have names, memorable personalities, and truly appreciate and believe in your vision, and in extension, believe in you. I am fortunate enough to have a few loyal henchmen who I'm sure will be able to secure the device without incident. For them I am grateful, and they will be amply rewarded.
It's very good for a villain to have trusted aids, treat your best henchmen well, and they will not fail you.