Germany main source of energy is still, by far, coal (lignite to be precise), and it's not going down yet. The expansion of renewable energy, which is very real, is being done at the expense of nuclear energy.
I wish they would be doing it the other way around: closing coal power plants before the nuclear ones. But Germany has lignite, and doesn't have much of a nuclear industry, so economically it makes much more sense that way...
Sure, it will eventually decline. But when you see the sharp decline in electricity produced from nuclear power plants, it feels like a missed opportunity to lower CO2 emissions faster.
I'm only looking at this from a greenhouse gases point of view. Maybe German nuclear power plants are particularly unsafe and it's better to wind them down quickly? I doubt it, which is why I lean towards an economical (more so than financial) decision.
Nuclear energy generally depends on the political will for the state to (in effect) take on the cost of insurance for the most serious accidents, since it is impossible for the energy producing companies to buy such insurance. It looks like in Germany that political will is no longer there.