I get the feeling that it's almost like bullying if your point of concern was that a much stronger player exploits you for resource.
However, with the looks of screemshots provided, to me your concern is not with strategy of players, rather the new players planet placing algorythm.
You are not in an disadvantage if an inactive player is in your primary solar system.
As I understand it, according to your level of expedition research, you are only bound to certain slots in any given solar system but not to a specific solar system itself.
So no harm done.
It would be a different story if the player was trully active.
Then maybe you would have a point.

I get it's annoying to spread out your colonies throughout various solar systems. But then again it have certain advantages to it.

Much Love.