You're right, it doesn't make sense. Just like it doesn't make sense to hold Gab.com to unreasonably high standards, while letting Twitter and Facebook get away

You're right, it doesn't make sense. Just like it doesn't make sense to hold Gab.com to unreasonably high standards, while letting Twitter and Facebook get away with exactly the same things. YouTube also left up Elliot Rodger's YouTube channel for like three years for similar reasons, until they changed their minds and took them down again. What it looks like to me, is that they just like censoring things and throwing their weight around, and this moral grandstanding is only after the thought.