When titles are changed, the intent as I understand it is to nudge discussion towards thoughtful exchange. Discussion is forever threatening to spin out of control towards flame wars and the moderators work hard to prevent that.

I think that if you want to understand why it might be helpful to change the title, consider how well "NVIDIA is full of shit" follows the HN comment guidelines.

I don't imagine you will agree with the title change no matter what, but I believe that's essentially the rationale. Note that the topic wasn't flagged, which if suppression of the author's ideas or protection of Nvidia were goals would have been more effective.

(FWIW I have plenty of issues with HN but how titles are handled isn't one of them.)