It is hard to argue against Chris or you since you guys know it better almost always, but I can't help myself disagreeing with you.
If I had to choose between 10k who want push and 100k who don't really want them, I would always go with the 100k. Because the 10k is already included in them, since they will go with it no matter what, but having the extra 90k is just a bonus. It is like the old Google game. Would I want 100 active users or 100k visitors through Google? I want the possibility of converting those random visitors to real regular visitors. Just like I want those 100k "so-so" users who don't really want push but I want the opportunity to introduce it to them and to convert them wanting the push.
I think for websites when it comes to users/visitors it is always quantity>quality. Activity is so essential that nothing can beat it. And our forums need the visitors, need the interaction. And if push is the way to go, then be it. The more we can reach the better.
I really don't see any advantage for an "advanced mode" hiding this stuff behind settings buried somewhere. As a visitor, I see your angle, you are worried about spam. But we are website owners, we must do what is best for the site unfortunately.
But I am not advocating to spam the visitors or to abuse the feature or somehow trick them. It all depends on how it is implemented. So I have to see it first and make a judgement based on that. Right now theoretically I want it as easy as it can be for the user. No hurdles, no annoying stuff, 1 click to-go. What is the worst thing can happen? Them disabling it? Well, right now the number for iOS push users is 0 anyway. So we can only win from here on, even if some disable it back after enabling it. Obviously I want the retention of active push notification holders high and imo PWA is doing the opposite of it. Not many will use it. But this is without knowing how the end-product looks, just based on theory.