Not the person you responded to but:

At the same time, for example, the west poured a large amount of money into rebuilding and bringing the east back up to the modern standards - see the Solidaritätszuschlag.

Rebuilding what? West Germans poured money into making banks. That's it. They closed down or sold off (and then mostly closed down or downscaled) all publicly owned industry. East German unemployment is double that of the West German unemployment. They privatized state-owned homes, then let them dilapitate or raised the rents to extraordinary levels. The life of the average East German was much better in 1988 than it is now, by any metric: access to services (education, healthcare, etc), buying power, coloric intake, life expectancy, employment, happiness, housing, vacation time, etc.

They didn't pour money to "modernize" East Germany. They gave money to industrialists, bankers and politicians to perform capitalist shock therapy on the East Germans. The results were massive profits for a few West German and the impoverisation of the entirety of East Germany

suddenly have a whole bunch of excuses as to why those people there support fascists.

Those are not excuses. Those are reasons. I don't like them either, but doesn't make it less true.