They shit on other projects all the time (frequently unprovoked, sometimes without the original conversation having anything to do about security). They also often reply with multiple posts with multiple paragraphs each when shitting on other projects. It shouldn't take very long to find an example if you trawl through their replies on Twitter, Bluesky, or Mastodon.

They have good points, but they're often either not relevant to the conversation or worded in such a way that it sounds like every project other than GrapheneOS is dogshit.

They also sometimes go on (IMO) paranoid rants about XYZ project systematically trying to destroy them or whatever.

If you want a direct example you can check their replies on Mastodon to about every topic.

I got heavily attacked for basically nothing like a year ago, which made me feel really bad and I still think about it frequently. Whoever treats people like this does not gain a lot of trust from me. Also such impulsiveness should not be involved in such a project. No one needs to be overly polite but also not that hostile against people and like 90% of other projects out there.