Serious argument? It doesn’t sound technically accurate. 

Let me explain: if “all the world” MySQL servers had internet open doors you sure could query all databases in the same way it’s done with websocket (nostr).

#nostr team seems unable to refute simple concepts. That’s keeping nostr very fragile and not resistant to any censorship. 

We’re being gamed. 

 But you can't. That's my point. No one is writing applications to that query the world's SQL databases. 

 No one is going to have an open relay at 0 cost. 

That’s why they block “spam”. 
Any server maintainer want to keep only his opinion-like-minded “good spam”.

Neither MySQL, Mail or websocket (nostr) will relay anything without a pre-filter.