If you look in the Haskell 2010 report the Goals section states that Haskell was designed for teaching and research and applications (in that order) and that th

If you look in the Haskell 2010 report the Goals section states that Haskell was designed for teaching and research and applications (in that order) and that the design committee intended that Haskell would serve as a basis for future research in language design. Usable for applications here means that it should be stable (_e.g._ so you can write your research tools in it and as a common language for sharing code examples in the academic programming language research community). Market share in the greater software development area (outside academia) was not one of its goals.