Might be something about empathy. If you got into a car accident and were lying on the street with a removed limb, would you like random strangers taking photos of you?
There are a lot of things I would like and not like, some of them more reasonable than others. If government is intended to prevent violation of rights, ‘not liking’ being photographed in public seems a poor justification for imprisoning someone.
Germany takes personal rights in such situations a lot more serious than other countries. E.g. you can't just take pictures of other people in public either - extra penalty for accident victims just expands on that due to extreme circumstances and their helplessness (and gives police the power the act immediately, vs the victim that might not even know having to pursue it afterwards)
Imprisoning photographers of the police is a already a punishable crime in France. So do we call the leaders like Macron an autocrat or dictator like we do in other countries.
Meanwhile cops and national guardsman violently attack journalists and protestors and their phones in all the protests ranging from Ferguson, Baltimore in the Obama era to the George Floyd ones in the summer under Trump era.
Germany is not France. No German court will not punish you for filming an officer abusing a civilian/protestor/etc. But you will be punished for taking a gore video of someone dying.