There are a lot of reasons to study ethics - not least that you need it to be a well-rounded philosopher; having more than one are of competence is a plus for future employment too.
I understand your reticence. The first few years of my undergraduate degree I wasn't a fan of ethics - I couldn't see how it could ever lead to precise answers. But I think now that I was missing the point. Most ethics specialists (other than possibly Peter Singer) admit that it's a complicated things and there are no easy answers. Ideally, I think the study of ethics can help encourage the development of phronesis - practical wisdom, though you should avoid letting logic blindly override the context of the society that you're in. Learning to take a step back from these decisions is a good thing, and I wish more people could learn that skill.
Most of all, I guess I've come to accept the view of many philosophers, not least my PhD co-supervisor Joe Mintoff, that the study of ethics isn't always about coming to absolutely correct views, sometimes it's about coming to relatively better ones. (You'd probably enjoy talking to Joe - he started off as a computer scientist before taking up philosophy, and is a pretty good logician besides).