Nodes will then have to follow the rules ascribed by miners, and their vote is pointless as consensus is formed by those who mine. Which means, Adam will still get kicked off the network, when the winning miners decide on 2MB blocks, and Adam only accepts 1.1MB.
You go wrong in thinking that miners are all-important. I clearly stated "the majority of nodes decide the consensus", not only miners.
As other have stated multiple times in this thread, miners have to be sensitive to where the real money comes from, ultimately.
As such, the "vote" expressed by BU nodes through the settings they choose to run, is an important piece of information to miners.
It is certainly not pointless. It would be pointless to ignore it, as a miner.
If it is supposed to be a "vote" then I agree with the other comments here that it is trivially sybil attackable and pointless. If it is supposed to be an anti-spam protection that avoids having your node flooded by huge blocks that the longest chain does not accept, that is not necessarily pointless. In the latter case, the miners will have to come to their own conclusions as to the "best" block size to produce, almost entirely independently of this propertied "vote" (using market research, experimentation, etc.). I agree with you that a "vote" of nodes is information, but it is almost worthless information so it should be almost entirely ignored.