It's because after german law, there's really no such thing as "Ausgangssperre" and all the things that have been so far done are not really things the government can do legally until there's an immediate danger, and the limitations regarding the vistation of public places etc. are legally poorly defined. (because something like this never happened and these laws didn't see a lot of trial) The government has to walk a tight rope between trying to protect the populace from a spread and doing what they legally can, as no, the rule of law hasn't been suspended and they still can get into trouble with the judiciary of the government as like every democratic western government, germany practices seperation of powers. I don't think anyone is happy about more limitations including the government, as these cost a lot of money directly and indirectly. You also have to consider the psychological effect. It's a bit damned if you do and damned if you don't - if you put big limitations in place you frighten the populace because they'll think the world is ending, which always causes some degree of destabilization. (just look at the crazy hoarders and the trouble they cause, most of them are just normal people that are really scared right now) If you see people behaving well and don't put limitations in place, they'll end up thinking this isn't as serious as it once seemed and they'll stop sticking to the rules to contain the spread, which will cause lots of people to die.
