Yeah in my experience most people don't like giving up the location of public apple trees etc. so they can harvest them themselves anyway.

How do you teach such norms, on small things like shared fruit trees, to adults? Which entrepreneurialisms to encourage and which to stop.

That is incredible difficult and basically boils down to resocialising people in another culture.

In the case of refugees we are facing the additional problem, that some originate from areas that are long time disfunctional, resulting in humans that never before have been socialized in a working society.

I believe that an important factor is to mix newcomers and locals, unfortunately that goes against the desire of both the government and the immigrants. Both want to centralize for efficiency resons.

when german people get free fruit: yes, that is well and good, the way the world is meant to be.

when non-german people get free fruit: aaaargh the immigrants are eating all the fruit! no respect for social norms! poachers! thieves!

Actually yes. Ingroup preference is a good thing.

Why is it a good thing?

Because it lets them feel good about themselves.

I love this new right-wing "intellectualism". They just declare "actually, racism is good" and then derive everything else from there

Nothing racist about preferring your ingroup. The arabs have a really good saying when it comes to this: Me against my brother. Me and my brother against my cousin. Me and my cousin against the world.

Why so?

better systematically harvested and sold than fallen to the ground and rotted

Animals will eat those or the composting of the food simply returns nutrients to the environment

i don't want the rats in my neighborhood to return those nutrients to the environment, and i don't like tracking composting fruit into my apartment, though i guess if parrots eat the fruits while they're still on the tree that's okay

Even better when done without profit as a motive, like community volunteer efforts such as https://www.portlandfruit.org/

that's better if it works better, but often profit is what works better as a motive. ultimately what matters is that the fruit finds its way to hungry mouths—and that those mouths are human mouths and not rat mouths!

systematic harvesting is much better at that; whatever kind of point-scoring exercise people engage in on the way is irrelevant

Commercial orchards are full of carefully pruned and closely spaced trees of known varieties and the margin is still not great on fruit production. It simply isn't a good way to make money to drive all around town picking unknown variety fruits with pest blemishes from irregular trees and then try to sell them. This is why maps like Falling Fruit have been around for years and yet if you walk around Berkeley (for example) you will still see plenty of fruit on trees.