I agree that these opinions seem unpopular. But I am not sure if they are. Most people oppose war and even in the Ukrainian war, they support some realistic way of stopping it. Its the job of popular media to make sure that these people feel alone in their opinion and that they believe that most hate the other side. Then there seems to be popular support and funding of the war effort. Good read that you might already know is Manufacturing consent by Noam Chomsky. The sole reason I'm on lemmy is because it still has some realistic community, unlike other sites which just have bots spamming the 'popular' opinion. For example where I'm from the correct opinion is to support Israel in all its efforts against Gaza. If one were to read the comments on common articles, which are trying to apologize or shift the blame to others for Israeli war crimes, he would find very strong hate of the clear victims. Yet Ukrainians, all not just the victims, have almost ideological support here. Again something found in Chomskys book regarding unworthy victims.

What counts as a "majority?" If you mean the majority of sh.itjust.works users, then no, Communist opinions aren't going to be popular. Lemmy.world? No. Outside of instances that are generally right-leaning? Depends, but usually more people agree than not.