Adam back talked recently about how the number of nodes as a measure of security / decentralization:
Yes he did:
If you boil it down going down from the requirements about what Bitcoin is and why decentralization and permissionless innovation [are important], you can translate that into what are the mechanisms that make bitcoin secure, and the full node auditors its not just running a full-node, you have to actually use it for transactions. Its the amount of economic interest that is relying on full-nodes and has direct trust and control of those full-nodes. This is what holds the system to a higher level.
That's the key. As a transactional participant you have to be
running your own node to get the security benefits he's talking about. So that is individual merchants, investors, exchanges, etc. Setting up a system to pay people to run nodes independently is exactly
not what he is suggesting.
Anyway, this is independent of my point that you can't use paid nodes as an indicator of interest and support for the coin (across coins).
We can agree to disagree about whether nodes-for-nodes-sake is a desirable goal. I will agree that if you think it is then incentivizing them is appropriate.