It's because of their ideology. To Hitler's government, the extermination of the Jews as well as the mentally/physically challenged, the Roma, and all kinds of LGBTQ was seen as being as important as knocking France out of commission, bombing Britain to capitulation, or destroying the Soviet Union. The Holocaust wasn't seen as some side project, it was an actual war goal and taken as seriously as anything else in the war.
Don't look for it to make sense, little of Nazi ideology makes sense.
Sad to say, but it's likely some of this bump they're getting is TYT listeners/viewers leaving after Cenk and Anna's latest spar with literally everyone near their orbit (and even losing some contributors). Many -oh so many- disaffected MSNBC viewers turned to non-traditional media after 2016, I cannot imagine how many might be leaving for more actually progressive sources after the recent election... but TYT has fumbled the bag here by both attacking other progressives AND doing shit like Charlie Kirk "debates" and interviews with Tucker Carlson.
I really hope they turn the ship around, because going after MAGA die hards isn't the answer. At any rate, Majority Report seems to be doing just fine so there's that.