It's important to remember that a large portion of the Showa period was spent in intense warfare, first with China and then against Pacific powers.

Strict rationing definitely impacted the availability of meat, or any food stuffs beyond the absolute necessities.

And then it only got worse when the air campaign began. Bombings wiped out distribution centers, roads and rail stations, factories, processing plants, cities, communications, etc. Many lived in urban centers and they were now cut off from much of their food.

Imports were also virtually impossible to get because of the incredibly effective blockade. By the time World War II ended, millions of Japanese people were quite literally on the verge of starvation.

The direct post war period, when Japanese people were under occupation and busy with restoration, was a similarly hard time. Many were homeless and struggled to find permanent shelter. Food was still hard to get, even with tons of food aid pouring into the country.

And of course, Japan was not nearly as rich as it is today for much of the Showa period. Rather, the average income and wealth of Japanese people was relatively very low compared to what it is today.

Today, the amount of plenty and accessibility to virtually any common good that they could wish for is unmatched by any other time in Japan's history. Even after two decades of economic troubles, Japan is still third largest economy in the entire world.

Finally, the reason why you often hear about references to the Showa period today, in the boom years (pre-1991 depression), the very lucky children grew up hearing stories about how much their parents struggled during the post-war years. Stereotypically, 'back in my day' stories about how difficult it was, how little they had, and how much they worked to make sure their children wouldn't have to suffer the same way.

These people went on to have children under the reign of a new Emperor, the time period being called the Heisei Period, which started in 1989.

The children who were born during the Heisei Period are only recently becoming adults, the oldest ones ranging from 20~26. Many are entering the workforce and are now old enough that their voices are being heard, their actions under scrutiny.

And of course, as with anywhere, times have changed and there is a cultural gap between the 'Showa kids' and the 'Heisei kids'.

This is actually a fairly widespread phenomenon for many in East Asia because of the numerous, life shattering wars that occurred around 50~70 years ago and the subsequent struggle to raise living standards afterwards. Many countries in Asia have come a long way in a few decades and these stories are very common.

Lastly, like in many countries, Japanese people today eat way more meat than they have ever consumed before.

Meat is more affordable, in relation to the average income, arguably more than it has ever been before. It is more accessible, higher quality, produced and shipped in greater quantities, and more easily obtained by the average person than ever before. This is true in just about every developing/developed country, not just Japan.

This is simply one more reason why.

If you have more questions, feel free to ask! Cheers