But I think the real reason might be even simpler: you can't tell what it does just from the name. What `map` does is consistent with well-known programming jargon. What `filter` does is consistent with the word's everyday meaning. But if you don't already know what `reduce` does, it's name isn't even enough to hazard an educated guess.
That's not true in Clojure because for lisp programmers for two reasons. First, `reduce` is a ubiquitous and well-known concept in lisp.
Second, in most lisps manually doing the same task with imperative code is an ugly verbose eyesore. But in algol-style languages, the imperative alternative is only 1-2 extra lines of very simple code, so using `reduce` is arguably just code golf.