It’s not a fear. It’s reality. It’s literally happening on HN right now.
Take this game, for example: https://news.ycombinator.com/item?id=47698455
Within an hour, someone had cloned the game with addition mechanics that multiple people mentioned they like more: https://news.ycombinator.com/item?id=47729573
That's not an AI company "slurping up data", that's someone using AI tools to accelerate their own personal clone of a project.
Why is that a bad thing? Person 1 built a thing, and then someone came along and made it better? It's a game, so better is subjective, but should ideas only ever come from Person 1, while everyone else just gazes upon them with slack jawed awe, unable to contribute?
I read simonw's comment not as dismissing the reality, but rather highlighting the harm of discouraging sharing.
The slurping can be both real and the induced reluctance to share a harm.