Pragmatic agnosticism is not un-philosophical, though, because it is derived from the application of the philosophy of Pragmatism to the question of whether we can know if any gods exist. It does not necessarily make the positive assertion that we can't ever know if any gods do or do not exist; instead, pragmatic agnosticism asserts that knowing if they exist or not simply does not matter.
Pragmatism is a broad philosophical movement, but most forms center around the idea that a proposition is true if and only if it "works" and that a proposition's true meaning can only be determined through the consequences of actively applying or trying it. True, meaningful ideas should be accepted while those ideas which don't work, aren't meaningful, and are impractical should be rejected.
Pragmatic agnosticism thus finds that the proposition "we can know if at least one god exists" is false and/or meaningless because the application of such a proposition to one's life does not "work" — or at least does not create any meaningful difference in one's life as opposed to not applying it. Since alleged gods don't seem to be doing anything for or to us, neither believing in them nor knowing about them can make any difference to our lives.