If country A gets a technological power by being first to it and while doing so being completely irresponsible for it - not one bats an eyelid. Why? Because it makes that country the big bully in the room.
US is country A here and has done this with Nuclear Strikes on Japan, worse debris through ASAT testing and a bunch of other such technological advancements. Why would a big bully in the room play the holier-than-though card later on? It is a mix of making the mistake and regretting it, but also serves as a way to ensure no more countries get that power. As this could result in lesser opposition power in global politics. For there to be balance in global politics, it is not right for just the first 1 or 2 countries to have vast technological advantage.
The new thing people from big bully countries have come up with is the term 'whataboutism' which is nothing but another ruse of moral high-ground. Just by telling others that they indulge in 'whataboutism', they intend to shut them down. Reality is that no country is good, not a single one when it comes to the game of power. Because you have to be equal to your enemy to deter them from attacking. This is the unfortunate truth no one likes to hear.
If Country A shares its knowledge with other countries, then there would be no need for others to do their own testing. But will they do that? Despite all this, testing done by India results in shortest amount of time the debris lives in space. By my oh my, the superior moral ground card played by everyone is extremely cringe-worthy. India had to do it to toughen itself up against its neighbor China. Do you know China also occupies a part of Kashmir and made it their own (mostly for the sake of aerial advantage with the Himalayas is my thinking)