Why are we trying to supersize drones and not use helicopters?

You do have less unique moving parts. Just one per rotor, all the same.

I think that's a big plus. No jesus bolt, no variable angles of attack, no gearbox. I also don't know how well electronic motors scale, maybe a bit smaller is better?

1. Because drones are really cool.

2. Because throwing cpu power at them to solve the stabilization issue turns it from a mechanical project to an electronics project, which appeals to geeks everywhere who don't have much of any fabrication experience.

3. Also, see #1 above :)