German people demand a safe permanent solution simply because time has shown over and over again that nothing is as permanent as an unsafe "temporary" solution that ends up being permanent because of inertia, budget cuts, insolvencies or whatever.
It's the same as with tech debt, with the difference that your average startup's tech debt can't be turned into a dirty bomb by flying an airplane into it.
And nothing is as expensive and company-killing than complete tech stack switch and rewrite of all software.
>unsafe "temporary" solution
There's nothing unsafe in this particular temporary solution. It's the other way, if something leaks, you can relatively easily fix it. It's only problem if you bury leaking stuff underground.
Also, proper solution is to use "waste" in breeder reactors, which only problem is political opposition to them.
1) Store the stuff above ground => risk terrorism, sabotage and "normal" accidents (e.g. lighting strike, earthquakes, corrosion leading to leaks), additionally: no one wants to live next to a nuclear dump so you won't get political support but rather fierce backlash from the people living near the chosen site
2) Store the stuff under ground => risk of collapse, of leaks and other issues as have already happened in the existing attempts
> Also, proper solution is to use "waste" in breeder reactors, which only problem is political opposition to them.
Breeder reactors IIRC have the problem of plutonium proliferation, molten-salt reactors aren't even close to being developed enough to be put into production.
It's the same as with tech debt, with the difference that your average startup's tech debt can't be turned into a dirty bomb by flying an airplane into it.