Do you agree with that policy?
That is really unfair for expats!
What was your reasoning for welcoming that idea?
Also sorry for being annoying with my questions

, but I am legit interested in your answers.
Do I agree with it? Well, of course Singapore (country in question) won't revoke my PR for a petty crime. They might simply not renew it the next time around. I have seen cases where it got revoked for more severe offenses. Seeing that even illegal migrants to Germany commit crimes and not being repatriated, I can fully understand people's frustrations. You move to a country, you better respect their laws and cultural norms.
Germany treating their own citizens (esp those abroad) poorly, has in my own experience a long tradition. Let me give you a few examples.
1. 1992 in Wellington, New Zealand. I was studying at the uni in Wellington back then, when some Indonesian classmates told me that they had been invited to their embassy to celebrate their National day combined with the fact that they had won their first Olympic Gold in Barcelona back then. I thought this was really nice. Not much later, with Germany's national day approaching, I decided to call the embassy to inquire about their own celebration. Mind you, it was early spring in New Zealand with hardly any tourists around. The entire uni had 2 German students. I called and the person answering replied my question about a potential celebration with: Do you have an invitation? No, so there.
2. Living in Singapore. Unless you are a high flyer expat, German embassy can't be bothered about your presence. There is zero information from them regarding anything important. Come election, they actually go all the way out to ensure you don't vote. You would have to fill in forms after forms to just get registered to vote, followed by the actual voting process. Now, that I live 25 years abroad, I am no longer allowed to vote at all. Compare this to my Japanese wife, the contrast couldn't be stronger. Every general election, their embassy sets up an air conditioned tent for them to vote in Singapore. They provide their citizens with regular updates on events and regulations.
3. As mentioned before, Germany's policy on citizenship. I might have considered taking up a second citizenship but this means I would have to surrender my German passport. I always assumed that Germany is just very strict with citizenship to find out, that people with for example turkish roots are given German citizenship even though they have still have Turkish citizenship. This then resulted in Erdogan campaigning in Germany for his reelection.
My reason for welcoming the idea of a shrinking population in Germany with an admittedly difficult transition period is simple. Germany (just like the entire world) has so many problems which are rooted in overpopulation, starting with housing, supply of energy, food etc. But no, Germany opened its door to allow millions of people to migrate without any proper plan how to deal with it. Housing is a disaster, cultural assimilation problematic etc etc. It's simple to me, Germany like other countries can't save the entire planet of 8 billion people. There would have to be controlled migration of skilled labor etc. Politicians have ignored this for the longest time and now reap what they sew.