I can understand why having nuclear weapons become more and more widespread is a Bad Thing for the world as a whole. That’s not the question. And I can also understand why a given country might find it in their interests to forgo nuclear weapons, as this might encourage potential rival countries to similarly forgo them.
But let’s suppose you have some country out there that decides that it’s in their interest to have them. What’s the basis for the major world powers - all with massive nuclear arsenals of their own - to get all outraged at this country for daring to have an arsenal that’s a small scaled down version of theirs?
Understood that might makes right, and if the major world powers are outraged about something - rightly or wrongly - that might have an impact, which is something to consider. But if I’m a leader or citizen of that aspiring nuclear power, I would find the outrage very hypocritical.
[This would not apply to countries who are violating treaties that they’ve signed.]