I'd wager this is because more Kindergeld would increase spending - which means either more debt or an increase in taxes somewhere else, and with the current government that's not possible.

And considering the CDU probably has more parents than childless people as voters, i guess that's a demographic they can afford to offend?

Then again, maybe searching for logic in this trainwreck of a government is our mistake to begin with.

This would definitely be better. It'll avoid some scenarios I wrote about in my other comment

Probably because even with your solution, there would still be a need to increase the amount everyone has to pay. That's still a hard sell.

By only making some people pay more, you're actually making it an easier sell because that limits the amount of people that will be upset because they personally will be affected. Those that aren't affected can be convinced with arguments.

That could also work but then we still have to increase the elder care tax as a whole. In the end the result is the same. Childless people pay more effective tax (taxes - benefits) than parents.