It's just a classic example of moral relativism. Sure, ______ *may have* done some "bad" things during ______, but they also ______.
The fact of the matter is that, despite the Holocaust and war crimes, the fascists were considered by - and no this isn't a slam here - the American and European left to be shining examples of how we needed to be.
The Nazis (or national socialists) and Fascists supported government involvement in the economy, supported socializing/nationalizing all trusts, supported secularism, supported separation of church and state, were one of the first environmentalist political parties, contributed to the origin of the green movement, opposed unregulated capitalism, supported tobacco prohibition, spawned the health movement, supported eugenics, supported social darwinism, supported gun control, supported welfare, supported big labor and unions, supported child labor laws, employed youth movements, supported corporatism, supported the abolition of unearned income, supported pensions for the elderly, supported land reform, demanded national education reform, supported redistribution of wealth from business, wanted lowered voting ages, supported the end of drafts, supported minimum wage laws, supported 8 hour work days, supported worker safety reform laws, wanted the stock market abolished, and demanded centralized government.
Yes, before we were at war with them, Fascists were widely idolized and considered revolutionary and progressive. The Fascists of Europe and American Progressives had much in common and often idolized eachother's policies, beliefs, written works, platforms, parties, movements, and politicians. There are countless examples of those on the political left showing admiration for the societies of Italy and Germany after their switches to Fascism. The Progressives saw Fascist Italy as a vision of the future, and likewise Mussolini looked at FDR's New Deal and saw an ally.
So it's important to understand that it's really not shocking that when you turn the clock back before the genocide and war crimes, you get policies that many on the left today (and even back in the twentieth century) find favorable. And that's where this moral relativism displayed here comes from. "Sure we all agree that the Nazis ethnically cleansed millions of human beings, but hey, at least they modernized highways and hated evil tobacco products." Once you get past the mass murder and bigotry, their policies and beliefs are still supported and applauded. This is just one example of the historical short-sightedness and world amnesia that exists today.
(Now no, and I can't stress this enough, this doesn't mean today that those on the left support genocide and whatnot)