Some time ago I wrote a posting on this subject in response to some musings of Nigel Warburton who tops his web-site with the citation from John Searle, "If you can't say it clearly, you don't understand it yourself". The question I addressed there was not one of arguing in some sense "in favour" of obscurity, whatever that would mean. It was rather one of positing the question of what is meant by appeals to the value of "clarity" in philosophical disputes between variant traditions. Generally speaking, the appeal to it is made by analytic philosophers arguing that some European thinker who they refer to is simply not worth reading or engaging with (and the appeal to Searle is particularly interesting in this connection given the "exchange" between him and Jacques Derrida).
For an interesting review that makes this point at some length and with some amusing moments see this piece by Mark Champagne over at Philosophy's Other.