I don't know anything about German politics so I'll take your word for it but again, in the case of Spain, you can't plan for a years worth of rainfall in 8 hours.
Nobody expected that much rain so it's hardly 'typical'. A more valid criticism would be if they had gotten rain in accordance with previous flooding events and it was still a shitshow. In which case go right ahead and criticise them.
The biggest issue is money like you say.
You can have 10 times the fire trucks and 10 times the firemen for the 1 in 100 year event that may or may not happen. And who's going to pay for all of this equipment and these people when they twiddle their thumbs for, possibly, 30 years, IN CASE something happens?
As usual it's a trade off between what you think might happen in a worst case scenario and what they can afford.
They're now getting criticised for 'wasting' money on the homeless problem and ignoring the fire threat. There's never enough money for everything at the funding that those in charge think they need. It's always a matter of competing priorities. Do they deal with the very real problem at the present or do they ignore that and put all our eggs in another basket?
Of course the solution is to fund both.
Good luck with that.