The problem is that RC planes almost universally require a much higher investment in skill-building to become competent enough to even fly, let alone fly well.

There is also a large community of builders and flyers [1], a network of clubs with actual airfields for the purpose, and a multi-million dollar insurance policy with membership.

Both the difficulty, the investment, and the training and peer pressure drastically reduces the number of participants who behave like asshats with their aircraft - to essentially zero.

With hobby drones, it is exactly the opposite -- just go buy some overgrown toy, and you can now put up in the air a device that with any of hundreds of failures of the device or pilot, can become a lethal projectile falling from the sky.

So, yes, serious requirements for anything over a few hundred grams is very reasonable[2].

[1] Academy of Model Aeronautics -- www.modelaircraft.org

[2](no, I'm not implying that the Govt automatically implements every reg in a reasonable & effective way, that could still end badly.)

[Edit: footnotes]