History

Two answers:

1. Taken as a straight question, probably. The allies evaluated the Nazis and determined that Hitler was so staggeringly incompetent at actually running the country and the war, and had such a lock on power, that getting rid of him would make defeating Germany infinitely more difficult, as more competent people took over. The exact motivations of the actual 1944 plot are still debated, but whatever you can say, the people involved were fiercely loyal to Germany and wanted to do it because they wanted good things for Germany in the war. That aspect of the question, weirdly enough, actually does have a strong parallel to the machinery of neo-fascism in America and Trump's incredibly fortunate position at the head of it, hijacking and mismanaging and squandering all the more competent people's effort that's been invested in it up until this point.
2. Taken as an obvious parallel with the attempted assassination of Trump, political violence in America is very clearly a bad thing at this point. We're not in 1944; we're at the stage of the Reichstag Fire and Enabling Act, when it's still not clear which way it's gonna go. If we were a couple years from now in 1944, when millions of civilians of the wrong designations had already died in the camps and millions more soliders and civilians in the concurrent hot war, then sure, knock yourself out. But trying to stop looming fascism through random political violence is like trying to stop a bear attack by covering yourself in steak sauce.