I guess I just have a fundamentally different view on open source than you. I don't see anything wrong with a company writing a tool in the way that is best for them given their current circumstances (e.g. skills of the team working on it) and then open sourcing it. The team that wrote this obviously felt that Haskell was their best choice for this project, and I don't begrudge them for open sourcing it just because it might not be useful for others.