It was just an example because just last week someone was claiming Germany should stop using the Olympiastadion in Berlin only because it was constructed for propaganda reasons.
The fact that Hitler is responsible for that doesn't necessarily make it bad. A horrible person can also do a few things right. You can acknowledge that without praising the guy.

No of course not - Trump's a huge buffoon that loves dictators just for the fact that they are dictators. I was just referencing the "Are You Really Going to Elect a Guy Who Has Good Things to Say About Hitler?"-Part, since that in itself for me is not automatically a negative.
Ignoring that Hitler had positive traits, too, and pretending that people voted for a guy that was evil in all aspects is convenient but very dangerous - especially since it enables people voting for populists like Trump to pretend that he can't be as bad as Hitler (which is probably the case - but if Hitler is painted as this absolute evil it's actually very easy to make this claim without a second though. If you see Hitler as an opportunistic asshole that wasn't inherently evil just for the sake of it then that comparison is a lot closer.
Demonizing Hitler as some kind of comic-book villain is ignoring how complex the situation leading up to him becoming leader of the Third Reich was and how people didn't see him for how bad he was until it was too late.