Don Syme, Andrew Kennedy and many others that work for Microsoft are awesome. This doesn't make it any less of an appeal to authority that's not valid. The reality is that their creativity was limited by the constraints of .NET

> The big ML-.NET type system mismatches have to do with things like pervasive overloading in .NET making type inference difficult, nothing to do with reified generics

You've hinted at a side-effect, but no, it has to do with subtyping [1], which naturally leads to co/contra-variance [2]. Or to put it bluntly, in a nominal type system that has sub-typing, Hindley-Milner type-inference is not only "difficult" but actually impossible. And because F# had to be interoperable with .NET, then it needed C# generics. Pity, because there's many things that F# misses, like Ocaml functors, structural typing, type-classes, higher-kinded types and the list can continue. And I just love how List.sum<^T> is defined [3] (static member, FTW).

[1] https://en.wikipedia.org/wiki/Subtyping

[2] https://en.wikipedia.org/wiki/Covariance_and_contravariance_...

[3] http://msdn.microsoft.com/en-us/library/ee353634.aspx