I strongly suspect that this "divisive" nature of the topic is precisely the illusion being created. That's exactly what I am challenging here.

In my non-online life I've known many vaccine skeptics, climate skeptics, crypto enthusiasts, extreme right/left-wingers, people with complex view of trans issues, divisions on BLM topics, gun fanatics, gun abolitionists etc, etc.

But the opinion around what's happening in Gaza right now doesn't fit into this category. Regardless of political opinion, outside of Zionists, I have not met anyone who will not, in private of course (for the reasons mentioned previously), agree that what's happening in Gaza is genocide and is not in the interests of the United States. The strength of the opinion can vary, but the general direction of opinion is consistent.

Another reason I added "clearly" is because, compared to say climate change posts that are often filled with climate denial comments, there are typically very few commenters engaging in any controversial discussions. Nearly all the top level comments are in agreement, the majority of the replies are as well. Compared to genuinely controversial topics which often do quickly devolve into impossible arguments.

There's also the broader issue that silence is not always a neutral position. When one side benefits much, much more from silence than the other, you can't simply shrug your shoulders and say "well it's controversial so let's not talk about it". In this case, silencing conversations about the genocide in Gaza is very beneficial to the state perpetuating this genocide and likewise very harmful to the people suffering from it.

The strategy is simple: make the topic appear to be more divisive than it is, which makes it easy to silence as "divisive and emotional", which is essentially the most desirable outcome.