Let's not forget the Silverlight debacle too, that made a looooot of entreprise people unhappy.
But one big difference is: Official support means updates in case of critical vulnerabilities and guarantees that, at least with IE11, it won't simply stop working after an update.
ASP.Net Core 1.x won't have any such guarantees after 2018.
And that's kinda hefty when the ASP.NET Core website (https://docs.microsoft.com/en-us/aspnet/core/) still refers to this page for guidelines as to which .NET Runtime to choose for ASP.Net Core(!) projects:
https://docs.microsoft.com/en-us/dotnet/articles/standard/ch...