There's multiple things at play. Until the F# stdlib was ported, F# couldn't target WinRT. Then there's the ton of fanfare JS/HTML were given, and the fact that C#'s development has been moving at a snails pace (and the "face" of C# is now working on making JS suck less) -- eh, it makes people nervous. Plus, MS's messaging wasn't all that clear. Now I see WinRT as being for cutesy tablet apps and I'm not so concerned. But before Win8, there was a lot of confusion going on.