This is still splitting the ecosystem. This is the exact same mistake they made with the json project format. Also, if you started using asp.net core 1.0, and

This is still splitting the ecosystem. This is the exact same mistake they made with the json project format. Also, if you started using asp.net core 1.0, and you do actually do need stuff that's .net 4+ only, you're stuck. There are a ton of people/businesses that use old .net libraries, that now have no way forward, no way to gradually introduce asp .net core. I'm going to assume that, if this is a new policy, that all the other new core stuff (entity framework core, async enumerable) might also become core only, which would be an even bigger issue. Also, I can't think of a good reason this happen. Are they trying to force people to .net core? Was supporting two .net versions that big of a burden?