Some relays refuse to respect deletes.

I'm not interested in relays that are stores of all events. Most events are junk.
I prefer relay-side data transfers and the outbox model.

I don't work for Will. 

 Oh also it breaks clients that use any form of caching service like Primal.

Unfortunately, local or remote caches are one of the few ways Nostr will stop using gigabytes of mobile data.