What does the implementation language have to do with anything? Sure one could complain that the program is slow/buggy but I don’t think that has much to do with whether one likes the implementation language or not.
I feel like this is like complaining about tex being written in web or hg being written in python (hg being slow seems a more reasonable complaint).
I think with a program, the proof of the pudding is in the eating
I guess, it would be kinda harder to adapt Haskell to the client-side-only interactive web (but of course, people are trying [1]). Nowadays the availability in the web directly impacts its acceptance so it is not a separate concern.
That's kind of outweighed by the more relevant fact that the people who had the time and inclination to create the software preferred one set of tools, and the preferences of some after-the-fact passerby would obviously not factor into this kind of decision.
