I've tried to port a MVC project to .NETCore 2 a while ago, it was pretty painful mainly due to lack of @helper syntax in views (everything which relied to @helper had to be changed). Also, from what i saw, nobody is actually in a rush to "move" to .NETCore, most big shops still rely on .Net Framerwork , i still do some occasional work on a project which is using .Net Remoting :)
I know plenty of people that would love nothing more than to be up to date and to start using .NET Core, but many of them rely on certain libraries that simply aren't there yet. I know a load of Umbraco devs that are eager to make the jump, but until their CMS supports it, they're kinda stuck if it's a dependency.