If you compare any other massacre to it, you start trivialising it.
It feels though as if we trivialized other massacres because they will never hold up to a standard we consider to be beyond comparison.
You are right that comparing such events, as in "this event is less significant because less people died" trivialises the immense human suffering involved in the Holocaust. But that has to go both ways, and comparing the Holocaust to these modern events also trivialises the impact of these current events. Each of these events, indeed each of these deaths is a singular atrocity, a tragedy beyond belief.
I just want to butt in that while the meme is stupid, most women are not awful either.