From my understanding, the answer to your "why" is more than obvious. They are afraid of Russian countermeasures, primarily of cutting the Nord Stream pipes. (60% of German energy supplies depends on it. Same or similar goes for Italy, Austria, and even France.)
Think about it from the perspective of the average resident, i.e., in Munich and vicinity where the current temperature ranges between 1°C and 5°C (33.8°F - 41°F). How many of them depend on gas heating? As well, how and how long they may survive without it? What are the alternatives? (If current, how much and how long before the system overloads and collapses?)
Although, I believe the main government(s) concern is, in fact, industry impact and through it economic impact - in short, the money not the people.
I certainly don't support this war and invasion, but talking from the experience, unfortunately, I don't see any nation even less government who would sacrifice their earnings and comfort to help the Ukrainians. And therefore, I am afraid that they are more or less left alone, depending only on themselves.
All these announced sanctions, in my eyes, are only empty threats. The only eventual game-changer might be (ironic truth) Russian oligarchs, but only if some of those announced sanctions would affect their businesses and earnings. In that case, they might make some pressure on Putin.
Although I wouldn't count on that too much either, as history teaches us, it was never a problem for Russians to get rid of or even execute dissidents, no matter how rich or at how high position they were (starting from Romanov family and through later regimes further on). In other words, Putin (not the oligarchs or anyone else) still controls the army, police, and judiciary.