And it boils down to: what is the minimum size of the Bitcoin P2P network considered healthy/secure when it's mainly composed of nodes being paid by miners.
In my opinion, if full nodes are too expensive to run for enthusiasts and require funding by the miners, bitcoin will die.
Hence the 100,000 nodes, which would be government agencies, universities, big companies, big non profit organizations and enthusiasts (wealthy individuals).
There's no way bitcoin can survive with 1000 full nodes.