if you start paying nodes.
this will cause a fee hike to try to 'incentivise' nodes while keeping the miners mining
all that will happen is 10 people running 1000 nodes each to get 1000x the income of just running one node.
Well, that is an interesting hypothesis that seems perfectly plausible.
Either way, the lack of direct monetary renumeration for node operation has not so far proven to be a fatal flaw within Bitcoin.