Hiroshima was wrong because it attacked civilians. This was an attack on a threatening military site. Those warships they were striking now have potential to kill Ukraine civilians.
Military targets are always fair game in war. Civilian cities are not. Your comparison is not the same
Eventually yes, and depending on the scenario it deserves the criticism. But this was an attack on a warship that was in open waters. The chance to hit a civilian was very slim.
War will escalate. Total warfare is probably inevitable already. Russia attacked Ukraine. Any retaliation on a military target is acceptable until Russia forfeits everything Ukraine lost and pays reparations to rebuild what they destroyed.
Personally I think this will escalate to NATO eventually. I don’t want it to, but Russia is pushing its boundaries further and scaring a lot of people. At some point someone is going to have to declare war on Russia instead of waiting for Russia to do the same to them. People will die. It’s unfortunate. I wish it wouldn’t happen but I don’t think Russia will let it not happen. And the ball is in Russia’s court because the bar for not killing people is “don’t invade other countries” which is a pretty low bar to set.