Why not elaborate?
Some people have said that Germany (and Europe) would have been better off if Germans had been allowed to keep their monarchy. It's certainly possible -- no Hitler in power, maybe no WWII, no Soviets in Berlin -- but it's also true that most of the Weimar Republic's enemies ended up supporting the Nazis (or the Communists or both). For every die-hard monarchist or aristocrat who opposed Hitler, there was at least one who supported him.
Some people call the Weimar Republic Marxist because there had been Social Democrats in the government. Sure, but not every government was Social Democrat. Most weren't and those that had socialists in them were most often coalitions with middle class, middle-of-the-road parties. And those Social Democrats weren't Communists or Marxists. They'd formed the government that defeated the 1919 Communist Revolution.
People like to view politics as composed of two sides with opposite principles -- natural and eternal enemies. In interwar Germany, you had two rival camps -- Nazis and Communists -- bent on each other's destruction and the destruction of any political or social forces in between the two hostile factions. Anybody who believed in freedom and constitutional government was in the middle and better off with the civil liberties and representative government that Weimar offered than with either the Communists or the Nazis. To attack the Weimar Republic as Marxist is to do what the Nazis did.