I am more of a dog person myself.
I am strongly against this. Invalidating UTXOs that are 'spam' will eventually lead to invalidating UTXOs that are 'ilegal', and after several iterations, will lead to invalidating UTXOs that someone who makes it look like they have a big following doesn't like. Accepting this BIP will remove Bitcoin's censorship resistance property.
Further, the fee market already limits UTXOs.
It is also not required for all nodes to store all UTXOs in memory. Nodes could store UTXOs under a certain threshold on disk, and in the event any of these are spent, it would take slightly longer to validate those blocks/transactions.
But invalidating UTXOs / transactions / things Luke does not want is exactly what
Bitcoin knotscoin / Lukecoin is supposed to be.
But, they can play all they want. Since it seems the miners / mining pools / exchanges / crypto payment processors are sticking with core what they do does not really matter that much except for the noise they generate.
-Dave