Node runners are usually running a node, because they have made a conscious decision to be a participant in the network. There is no payoff beyond validating your own copy of the blockchain, broadcasting your own transactions, and private querying of the mempool and blockchain.

So you have to wonder what *kind* of people would do that, and the broad majority of those are pretty much ideological participants.

And your asking why ideological participants would go to the effort of #3, when they've already gone to all the other effort of running a node? Tell me you weren't around for UASF without telling me yOu weren't around for UASF.