I’m not sure they do know it. Like, they may hear it, but at least from those I’ve encountered, a lot of the positions advocated only make any sense if one fundamentally disbelieves in nuance. In such a case, one believes that there are good people and bad people, and that anyone that does any bad is irredeemably so and equally bad as anyone else that does any bad thing, and any good person is incapable of doing any wrong.

Thus, the idea that you could have a group of terrorists, who true to that description use terror attacks to further their aims, fighting against a genocidal state doesn’t fit, because fighting against a genocide is obviously a good thing to do, and good people would never do something like attack a child, therefore any reports of that happening must be a lie. Some conservatives do the same thing and just pick a different side, insisting that genocide can’t be happening because they believe Israel to be the “good guys” fighting a terrorist group.

That isn’t to say that the two sides of that conflict are equally wrong either, that position also lacks nuance since it misses that the scale of one crime can be much greater than another, just that some people will see any criticism of anyone fighting on the side of a victimized group as alignment with the aggressor.