I understand your point of view and agree with you.
Let me use a simile:
Most large shopping centers (at least in south Florida) provide free parking for their customers. The parking lot space service is obviously not free and someone absorb the cost (usually ownership cost and maintenance community fees).
Change this traditional free parking in most shopping center and charge the customer is not a good idea (it will create additional problems in the future).
- One solution could be accept donations at the shopping center entrance (maybe with an amazing sign with a lovely speech suggesting a donation).
- Another solution could be an optional paid service like valet parking or premium parking slots, (equivalent to premium bandwidth to download and perform the blockchain operations). I'm confident that some bitcoin users will paid a reasonable fee to have access to faster full nodes.
- Another real solution is to offer other related paid services like rent electric chair or high capacity shopping carts, sell umbrellas when is raining, etc. (equivalent to perform the Coinjoin service). At the end you will have the blockchain in the Coinjoin processor and your node will be idle until the deterministic selection will activate your node to execute the coinjoin transaction.