Because right now you are triggering the cookie banner reflex where a user just instinctively dismisses any warnings, because they want to get on with their work / prevent having their flow state broken.
There should also probably be some more context in the warning text on what a malicious repo could do, because clearly people don't understand why are you are asking if you trust the authors.
And while you're at it, maybe add some "virus scanner" that can read through the repo and flag malicious looking tasks & scripts to warn the user. This would be "AI" based so surely someone could even get a job promotion out of this for leading the initiative :)