[jhugo]

Those things are not as coupled as you make them sound: the vast majority of people getting paid interest on their ETH won't be running a node. They'll be receiving interest passed on by exchanges or other centralised entities that are staking their ETH.

[DennisP]

And if those entities give them some kind of token they can trade around, giving them rights to their deposit plus some profits, that token might well be a security.

But if I loan you dollars and you promise to do something profitable and give me more dollars back, that doesn't make the dollar a security.