Programming languages are seldom chosen because of the merit of their core semantics. Successful programming languages are coupled to some platform or ecosystem and it is the platform that is chosen. For example JavaScript could have been functional or imperative or whatever - it wouldn't have mattered for it's success. Objective C was obscure until the success of the iOS platform, C# was pushed by MS as the way to write Windows apps, VB was the way to script office applications. None of these languages became successful due to their core semantics.
Haskell will always remain niche since it is not coupled to a successful platform. But compared to the thousands of other "second tier" languages it is doing pretty well.
Haskell will always remain niche since it is not coupled to a successful platform. But compared to the thousands of other "second tier" languages it is doing pretty well.