I guess the simplest explanation is the most probable one. Scholz is unwilling to accept the economic and perhaps political damage from a gas cutoff. Germany believes that being too helpful to Ukraine might lead Putin to cut the gas and hopes that aid from others will be enough to blead the Russian army into impotence.
If Putin stops or is stopped to the east of NATOs border then Germany can eventually return to trading fairly freely with Russia and come out of this as just a slightly more rearmed and less pacifistic version of its pre Ukrainian war self.
Personally I think this is a foolish fantasy. Putin intended to take all of Ukraine, some of Moldova, all of the 3 Baltic states and perhaps half of Poland. After every successful slice (if any) he will reevaluate the West’s political leadership and decide if he can continue.
Putin’s disastrous miscalculations may have been enough to force him to stop with a piece of Ukraine, but the consequences of his continuing are so monumental that the damage to Germany’s economy from a natural gas cutoff pale by comparison.
I disagree with you on what Putin’s primary war aims were, but I do want to point out that the German government had painted themselves into a corner prior to the war, they just didn’t realize it. They had committed to dismantling their nuclear power plants (which to be fair, the Germans were oddly bad about designing and running) and reducing their coal plants in favor of ‘renewables’ and buying more nuclear generated electricity from France, plus natural gas generating plants. All to virtue signal about being committed to green energy.
Then the war happened.
It is politically impossible at this time for the German government to walk back the decommissioning of their nuclear plants or slow down the coal plant decommissioning program. There was just too much popular support for it. Renewables and French energy at the current state of development won’t keep the heat on in winter or the German factories going in summer without Russian gas.
They painted themselves into a corner. And everyone knows it.