Originally Posted by Poodleshooter
Because as originally proposed, the law was comprehensive to all short firearms.
Handguns were originally to be regulated as Title II weapons, but were exempted at some point in the process.
So as originally proposed, the NFA "made sense" so far as its goal of requiring registration of all concealable firearms.
Interestingly enough, silencers were originally left out of the NFA. The concern was that they were used for poaching during the great depression, so silencers were a last minute addition to the NFA Registry, and the handguns were leveraged out.