As a German, I don't consider this a failure. Yes, it was expensive, and probably it was more expensive than it needed to because execution wasn't perfect, but this year up today, Germany has produced 51% of the electricity via renewable sources. And of course Germany gets the same cost savings as anyone else when moving further forward with renewables. Also the guaranteed high prices for solar and wind from the early years are currently slowly running out, so currently those costs are falling quickly and the true cost saving of more renewables will be effective in the electricity prices in Germany.
"everyone else who tries it will do better because Germans ate the costs?"
Yes on both your points. Sadly, German industry didn't get the benefit. Which makes it harder to convince the country to do stuff like this again.
Very different from Tesla, where a bunch of silicon valley people ate the cost (e.g. VCs, roadster, 2012 model-S) and then many benefitted as they own stock.
They may have prevented a far larger wave of climate refugees than the current batch of migrants and refugees that have proved so politically costly for the ruling party in Germany.
And everyone else who tries it will do better because Germans ate the costs?