This also basically goes for East Germany. In practical terms it was annexed by the western side, looted for all its worth then had anything connected to communism dismantled and suppressed harder than nazism(west germany of course infamously at one point had more former nazi party members in the state than nazi germany had active ones).
So who is to blame for the poverty and for what reason? Well communism is suppressed so theres basically one other option for people to take unless they want to take the option of “things are basically fine.”