Why should metaphysics be a dead end? Given the facts of observation, what must be true of reality so that such facts can obtain? Metaphysics is tacit within the facts, and a metaphysical stance is tacit in one's claims. Everyone here would agree (except in some artificial, dishonest, rarefied moment of academic detachment from reality) that something cannot both be and not be the case. We could not possibly reason about reality otherwise. But why should logic take this position? Logic is concerned with correct reasoning, but reasoning is about reality. So the justification for the logical principle of contradiction can only be found in the metaphysical, that is, in the reality (or being) that we are reasoning about. It must be that reality (being) is such that it cannot both be and not be. It is the only way to maintain the faithfulness of reason to the real. Any attempt to undermine this correspondence undermines the very attempt to undermine this correspondence, as you would would no doubt be reasoning to such a conclusion. Thus we have the first methodological principle of first philosophy, that our conclusions cannot undermine the very means by which we reason to those conclusions. We are condemned to reason, so we better do it well as there is no other alternative, other than doing it poorly. This rules out skepticism and relativism off the bat (and incidentally, this is why even academic philosophers generally do not take these positions seriously). And ethics, of course, entails metaphysical propositions like anything else.
That these are difficult subjects often executed poorly does not mean they are bullshit as such.