And I wouldn't say it's anything specific to Haskell: I've seen a lot of times in other languages people trying to flesh entire libraries around a domain-specific primitive that go far beyond their current needs.
I'd say the Haskell community (its focus) is more "at fault" here, encouraging these kinds of exploratory rabbit-hole-diving. Though, to be fair, there are people there with get-shit-done mentality (github/bos and github/ocharles come to mind) and I see more of that kind coming in lately.
Pick the weakest structure that will satisfy your current needs and move on. (by ocharles, paraphrased)