I imagine most exit nodes are likely controlled by the US government and/or its close allies. Who else wants to have their IP address banned from most of the internet and potentially get visits from their country's equivalent of the FBI?
If most Tor users ran exit nodes and most people used Tor, it would effectively make internet traffic anonymous. But without those network effects, it is vulnerable by design to deanonymization attacks by state actors.
I ran an exit node for a while, and found myself auto-banned from so many services that I stopped running the node and threw away my IP range (which now would be worth $$$ - oh well!)
I ran Tor nodes, had a bunch of blacklisted IPs, and just stopped running them and it was fine? Blacklisting Tor nodes requires updating the data often, so it falls off pretty quickly. To discard an entire /24 would be pretty funny over that!
Most people just use a DNSBL to block Tor exit nodes. They're pretty trivial to find online and presumably, very easy to set up because the list of Tor exit nodes is publicly available.
This also means the expiry time is usually tied to however long a Tor exit node stays on the DNSBL + 3 or so days (depends on how long the software is configured, but 3 days is typically the assumed default for IPs that tend to get mixed up with automated spam, of which Tor is also a massive purveyor.)
I run an exit node, and I know several people who do, I dont suspect any of them to be anything but people who care about privacy, surveillance, and helping people get access to the free internet from restrictive locations. I admit, I bristled at your comment, because I do not like myself, the EFF, and many of my close friends being imagined as part of the US Government.