With a sufficiently long-term view, "what one can get away with" (including considerations of signalling, effects on self, etc) is not as scary as it sounds. It's basically just near-mode utilitarianism. And to me it's the only ethics that that doesn't seem to rely on confused notions like unknown absolute moral worth.

Most ethics discussions, even on LW, are more about signalling and bullying people into doing what you want them to do, rather the describing how decision making actually works. I'd prefer that there was somewhere we could stay descriptive instead of prescriptive since I think there's a lot more insight to be had that way. Separate the game-theoretical negotiation of establishing a society's ethics (which can take place anywhere) from the theoretical basis of how it all works (elucidation of which can only be done those sufficiently versed in rationality).