Hey, c'mon, we hit 1.0 on the tooling _weeks_ ago, with VS2017. Net Core has only been out since end of June last year. ;) /s

(I started working on a .net Core project in January last year, transitioning into it as a new language from PHP/Coldfusion - perhaps not the ideal learning path with all the changes between the betas/RCs yet quite exciting at the same time)

Now that we're here, though, we have e.g. NCrunch working with Core and from this point on it's becoming much more viable to develop in.

You can claim that it's very stable but the ecosystem (support, tooling, community, etc) is simply not there yet to make .NET core one of the most attractive techs in the market right now.