A huge fraction of tor usage is illegal. Drugs, and other illicit sales mostly. Some pornography. None of this is relevant to an exit node operator because the servers for these people are using hidden services, and as such their traffic never exits the for network, and never passes through an exit node.
The illegitimate uses of tor that require exiting the network are fairly limited, and tor isn't great since the list of exit nodes is public, and blocked many places. Mostly those users are trying to bypass a firewall or browse anonymously for one of the reasons that for advocates claim.
Humm yeah a huge fraction of it is illegal. In fact in some countries it is illegal to circumvent the restrictions imposed by the State on the internet. I am non trying to start an argument, but the concept of illegality depends on the laws and very often is completely disjointed from the concept of justice.
Is it illegal to buy drugs? Yes, in a lot of countries. Is it immoral? A lot of people think it isn't.
So, don't use the metric of the US judicial system to establish what should be considered illegal/immoral on TOR. TOR is a worldwide network and shouldn't be judged based on the laws of a specific country.
The illegitimate uses of tor that require exiting the network are fairly limited, and tor isn't great since the list of exit nodes is public, and blocked many places. Mostly those users are trying to bypass a firewall or browse anonymously for one of the reasons that for advocates claim.