Anything that questions their ideology (and by extension, their identities) makes them actually feel that they're being physically attacked. They extrapolate the suffering trans people endure from not being accepted into "if you don't validate my identity I'll kill myself, therefore by not using my pronouns/letting me into single sex spaces I don't belong in/having sex with me/telling me I'm a real man or woman, you are literally killing me." That's why they're always screeching about "LITERAL VIOLENCE."

do they think every guy/lesbian that does not want Girldick does not want it because they are reading up on TERF shit?

Yes. After GC went down a lot of them were complaining in other subs that the "terfs had invaded since their home was destroyed" completely unaware that there have always been people opposed to TRA ideology in those subs. Many who had never even set foot in GC. They weren't refugees from GC. But given that these types of TRAs don't know how to stfu, the "terfs got banned" celebrations kicked off and JKR bashing was back in full swing. This, of course, led to many rational people who actually read JKR's tweets to speak up and ask "but what did she do wrong? I don't see anything wrong with what she said" leading to these people being called terfs.

The black and white thought process is "only a bad person could possibly hold these shitty beilefs/not cater to my whims, so they all must be evil trans hating terfs."