But filters **_could_** make it very difficult, IF mining was sufficiently decentralized. The cost of out of band tx's should reflect the probability for a miner hitting a block. If mining is decentralized, that probability is low. If blocks are full, then the cost of an out of band transaction is that much higher. Decentralizing mining is the real fight. This move seems like they're trying to make that fight irrelevant, like someone is afraid they're about to lose. Is it coincidence that the Knots guys are also running Ocean? It doesn't look like it to me.

No it can't. And counter to your point, more decentralized mining may make it even easier. Decentralization of mining has nothing to do with how full blocks are. You're right, it's not coincidence. They're fleecing you. You've been convinced that mining on ocean and running knots is the morally superior stance.