Meaning of “Demo Nihon niha shiki ga arukara(でも日本には四季があるから)”

“Demo Nihon niha shiki ga arukara(でも日本には四季があるから)” means “But Japan has four seasons (so it’s still wonderful).
This is a relatively well-known kind of joke phrase used when unpleasant aspects of Japan come to light.

You might find it strange, but many Japanese people genuinely take pride in the fact that Japan has four seasons. However, unfortunately, in recent years, the long and overly hot summers have made it harder to feel the presence of all four seasons.

Example Conversation on X(twitter)

A: [Bad news] Japan is the most heavily taxed developed country in the world.
B: Demo Nihon niha shiki ga arukara(でも日本には四季があるから)…

A:【悲報】日本は先進国で世界一の重税国家だった
B:でも日本には四季があるから…