Sure, I understand why people want blocking. At the moment. 
Once webs of trust, sovereign, self-served clients, and personal relays reach their full potential, they won't "want blocking" anymore or even think about it. 

Even if blocking was somehow not difficult on Nostr-as-a-protocol (impossible, as already discussed), I would still rail against it as a norm and would encourage forking-away from anything that implemented it. It makes me uncomfortable that it's even perceived as being glanced at, side-eye. The fact that I can voice my opinion in a way that nobody except the listener can stifle is the reason we're here.