There are plenty of reasons pilots should be paid well. Long hours and the responsibility for an expensive piece of kit or even the fact that you do have to make the very occasional life or death decision are not reasons in themselves.
They are just part of the job, if you want to work out why a pilot should be well paid, start thinking about how the decisions you make on a daily basis can have a direct implication on the financial well being of the business. That's the sort of tack you have to take when talking to a management type about your "worth" to a business, not that your job is difficult or that you spend a lot of time away from home. That, is quite simply, what the job is like and none of us who fly for a living should pretend that we didn't go into it without knowing that we'd be working odd hours or ending up in odd places.