>You make it sound like this change was a snap decision. It's been known for at least 10 months now that project.json was going away. All the documentation I stumbled upon on github also made this clear.

Great and in those 10 months there was no alternative but to use the soon to be deprecated projects. And they released a 1.0 product like that.

Someone from Microsoft commented unofficially that there was pressure from partners who were using .NET Core in production to release a stable - which was very obvious and they put them self in a spot where they had to support a deprecated project.json system since people are using it in production while also developing the new system. Whoever decided on the release timelines dropped the ball.