Arguing about terminal values is pointless, of course. But morality does have a good and useful definition, although some people use the word differently, which muddles the issue.
'Morality' (when I use the word) refers to a certain human behavior (with animal analogues). Namely, the judging of (human) behaviors and actions as 'right' or 'wrong'. There are specific mechanisms for that in the human brain - for specific judgments, but more so for feeling moral 'rightness' or 'wrongness' even when the judgments are largely culturally defined. These judgments, and consequent feelings and reactions, are a human universal which strongly influences behavior and social structures. And so it is interesting and worthy of study and discussion. Furthermore, since humans are capable of modifying their behavior to a large extent after being verbally convinced of new claims, it is worthwhile to discuss moral theories and principles.
You're about where I am.
We have some in built valuations to behavior and reactions to those evaluations. Humans, like animals, judge behavior, with varying degrees or approval/disapproval, including rewards/punishments, Where we are likely different from animals is that we judge higher order behavior as well - not just the behavior, but the moral reaction to the behavior, then the moral reaction to the moral reaction to the behavior, etc.
Of course morality is real and can studied scientifically, just like anything else about us. The first thing to notice ...
Do you believe in an objective morality capable of being scientifically investigated (a la Sam Harris *or others*), or are you a moral nihilist/relativist? There seems to be some division on this point. I would have thought Less Wrong to be well in the former camp.
Edit: There seems to be some confusion - when I say "an objective morality capable of being scientifically investigated (a la Sam Harris *or others*)" - I do NOT mean something like a "one true, universal, metaphysical morality for all mind-designs" like the Socratic/Platonic Form of Good or any such nonsense. I just mean something in reality that's mind-independent - in the sense that it is hard-wired, e.g. by evolution, and thus independent/prior to any later knowledge or cognitive content - and thus can be investigated scientifically. It is a definite "is" from which we can make true "ought" statements relative to that "is". See drethelin's comment and my analysis of Clippy.