> It has 995 open issues in its Github repository.
This is not a sensible metric for code quality. For one thing, only about 20% of the currently open issues are tagged as bugs - more than that are suggested improvements.
> Haskell program was supposed to work right if it compiles, wasn't it?
No. Especially for tasks like string manipulation and format munging, you cannot capture the complexity of the domain into types.
https://en.m.wikipedia.org/wiki/John_MacFarlane_(philosopher...