I think there are a few contributing factors for why NIP-60 isn’t more widely used.
The first of these reasons is that it is actually a really new option available to Nostr clients. NIP-60 has only been around since October of last year, and it can take a while for something like this to gain wide adoption, especially with more established clients with devs who likely already have a roadmap of things they are planning to add.
Another major reason is that NIP-60 wallets are always custodial, because eCash is a custodial system. Bitcoiners are rightly averse to anything that would exclude the option to self-custody.
Finally, anything like this should be opt-in on the receiving user’s side. Not only since some users won’t want to receive custodial sats, but for a more practical reason, as well. As I understand how this works, I could receive an eCash zap on Olas for an image I posted on Amethyst, and it would go to a NIP-60 wallet that I never intentionally set up and would have no indication of how I could retrieve from Amethyst. Indeed, because zaps are for small amounts, I may not ever notice that the zap never went to my Lightning wallet. I might just assume it did, even though it is sitting in a completely separate wallet I have no idea even exists.
Yes, I am the only one who can access that wallet, since the eCash is locked to my npub, but that does me no good if I have no idea I need to do anything to access those sats. The experience would be even worse for someone new to Nostr and Bitcoin who joins on a client with no NIP-60 wallet, and they see they are receiving zaps, but they have no idea what that is, where to access it, or how to use what they received to zap others.
So, while the idea of a user being able to immediately receive zaps upon creating a Nostr profile is pretty cool in theory, it has some pitfalls in practice unless it is made opt-in for receiving.
Note: I may be entirely wrong about how NIP-60 works. The only app I know of that has it built-in is Olas and it was impossible to test this because Olas on Adroid is fundamentally broken. Nothing works. Half the time I can’t log in via remote signer. My Follow feed doesn’t load for several minutes, if at all. I select my existing Nutzap wallet, send it some sats that show up immediately (great!), but then the next time I open the app the wallet isn’t connected to Olas anymore, and when I connect it again the wallet is empty… When trying to select a feed, the feed menu pops onto the screen for half a second and disappears again. Tapping it over and over again gets the same result a few times until the menu FINALLY stays on the screen so I can select to view my “For You” feed. This feed is supposedly posts from people in my network, but a post I made on an alt profile that I KNOW I am following doesn’t show up in the feed at all and there is no way within the app to search for a specific profile… So, I am sorry if I completely misunderstand how NIP-60 works, but I did my level-best to confirm it first and simply wasn’t able to.
