The problem with a harder lockdown limited in length is that Germany is a member of Schengen, so even if Germany largely eradicated COVID within its borders, it could then be reimported from another EU country that hadn’t been as locked down.
You might advocate for Germany closing its borders earlier and for longer, and forcing police registration of fellow Europeans, but personally I think that is horrible. I see restrictions on free movement in Schengen and challenges to European integration as much more of a problem in the long term than COVID morbidity.
I am as pro-European as they get but what should we do when things go downhill as they did in e.g. Belgium or Czechia? We have no influence on preventive measures there. All we can do is to deal with it and to be as little affected by it as possible. Beside that, a more fine-grained control than national borders would be preferrable anyways in that case, so it would be not only be about locking fellow Europeans out but fellow Germans as well. There is no base in law for that though and attempts to limit visits between federal states have therefore been anulled by courts. Can we agree that it is not an easy situation?
You might advocate for Germany closing its borders earlier and for longer, and forcing police registration of fellow Europeans, but personally I think that is horrible. I see restrictions on free movement in Schengen and challenges to European integration as much more of a problem in the long term than COVID morbidity.