The old Soviet Union was a bigger threat than Russia is now. Their forces were already on the Elbe and they were the dominant power on the Baltic. Why didn’t Sweden and Finland join then? They needed it more back then. Because as I said, they were too frightened of what the Soviets might do to them. Remember the term Finlandization?
NATO was very large and powerful as well, and American forces were huge and included large tactical nuke defenses, at the time it was a total war or not.
Under Putin the threat is one bite at a time and relentless, both those countries looked at the attempt to capture non NATO Kiev and the boldness of Putin’s disregard for anything resembling normality and they felt under threat being also outside of NATO, yet with Finland also on Russia’s border like Ukraine, and for Sweden, Gotland island hanging there ripe for the plucking, they knew what they were doing and didn’t feel the need to get your opinion on their national survival and joining our alliance.
Another irony being that neutrality served Finland quite well for over 70+ years, with a demilitarized border and lots of trade/tourism with the Soviet Union and then Russia.
Now their economy has become stagnant, their border is being militarized, an occupation force being put in place and the former prime minister (a Social Democrat) who pushed them into NATO is now working for an 'international consortium' that includes Anders Ragmussuen, Tony Blair, Andrily Yermak, and Hillary Clinton, among others..iow she sold the country out.