The above commenter's point was actually drawing a distinction between these, and "one-upping" by saying there was a difference, or worse one, out of these extremist ideologies.

I disagreed and said that they are both equally horrid.

Expressing equal hatred for people and systems that kill countless millions through starvation, gulags/concentration camps, and disappearing them, is not childish. I have a ton of solidarity with victims of other evil regimes.