The best thing about being right is it doesn't matter if the listeners can process it, you're still right.
There are consequences to ignoring GrapheneOS developers. Insecure phones can get people killed.
The best arguments are respectful and measured, but few things in this world are ideal. It's in your best interests to tolerate any perceived "abrasiveness". Ignore the the guys who make Cellebrite sweat at your own peril.
Nobody at google will get demoted if vulns in grapheneOS can’t get fixed due to their oss strategy and result in deaths. Yelling at them angrily will not change this. When was the last time someone abrasive called you a moron and corrected you - did you come away feeling like you will take the lesson to heart and adjust your behaviour?
The argument about the seriousness of the topic seems to be to be arguing for taking into account human psychology and toning down rhetoric (note: not failing to make the claims, or dropping points, just changing tone) in order to make it more likely that you get listened to. To the earlier commenters point: it would be great if nothing other than correctness + importance determined likelihood of being listened to. But that's not the way the world works.