It's good to see C# catching up with the past decades of language research. Maybe it's MS's DNA - they're still heavily pushing C++.
Tooling is the only real reason to ever use C# over F# - C# just doesn't do much (anything?) better. That, and legacy/enterprisey dev.
Heck, C# 7's tuple support is exactly what F# used to do, but then capitulated to MS's idea of making System.Tuple, a reference (heap allocated) type. Now in C# 7 since they finally got around to being a bit serious, they implement a new value-type tuple.
I guess we should be happy for any F# support we get. And indeed, tooling for functional languages is poor in general, so F# certainly leads...