the reaction to jen psaki seems to miss the point in one extreme or another. she's not the parachuted-in fool that some people want to cast her as, and she'll prove that from time to time by citing an obscure regulation or law - often catching the journalist (who has been carefully manipulated for low expectations) off guard. nor is she the calculated, conniving insider some people want to pretend that she is. there's little reason to think she knows more than she lets on knowing...
rather, she's simply a public relations expert that doesn't know a whole lot about the ministry she's representing, but doesn't need to in order to present the proper face on it. that she was put in the position she's in speaks a lot about the administration's perception of how the media should be dealt with. they didn't put somebody there that knows a lot about the ministry and can explain complicated things to reporters. they put somebody there with little understanding of foreign policy but that has a masters in manipulation, with the aim of controlling and shaping the message in the way most beneficial to it.
her undersecretary (marie harf) is clearly far more knowledgeable and is probably the actual go-to person in the office.
i think the point is not to shoot the messenger. she clearly knows how to control the message in a room of reporters, which is what her job actually is. the concerns - and they're real - should be directed more at the people that gave her the job.