I don’t agree – if there is a chance that anyone can ever join the site who is unfamiliar with the software, then a basic set of bronze badges that teach the software are always required. If everyone who joins is already familiar with the software, then the bronze badges can of course be ignored.
If your argument is that all gold badges should be completely custom and 100% tailored to the community, that’s fine, but someone has to do that work – since you’re defining them as custom, that’s outside the scope of what Discourse itself can offer.
I’d also argue, at quite some length, that long term participation is critical to the survival of any community, regardless of how specialized it may be. So to the extent that the built in silver and gold badges incentivize repeated, long term participation, they do in fact fit all communities in that sense.