The point is that it's clearly not just a less maintained, less tested implementation. It's 1.61x faster for one in real world apps, in some case even almost 4x faster.
Definitely not. They said they don't feel good using it because it's less maintained and less tested. They mentioned "we can't learn from it" to provide an example of a secondary benefit that this project could but (arguably) doesn't have. In other words, they had a pretty good reason not use this and didn't see much value if they couldn't use it.
You made it sound like they had some ultra extreme view that software is only valuable if you can learn from it.