I don't have the answer to your qustion, but I like to occasionally consider that there is no such thing as a stupid action, only an action that I don't understand.

Why would someone talk like that?

Some possibilities:

1. To stem all future criticism of Kagi by making the first and the most at the time visible criticism sound braindead. Thus creating an association that all of criticism is braindead.
2. To use the reverse psychology to promote Kagi. You say it sucks, and you don't think it's worth your time to even explain it? Well, I am a rebel, so as a fuck you, I will use Kagi.
3. To further lock in the attention and the mental resources on Kagi. Love it or hate it, be indifferent to it, but here we are thinking about Kagi. Kagi's profile has been raised.

These three immediately jump at me, because I see people preaching Kagi in a manner of an influence op.

So these negs could be part of the op.

Again. Not saying I know. I don't. And I likely won't use Kagi myself. It's just fun to speculate a bit.