Bob:
I've flown with guys that have shown the same attitude like you. Those flights are the ones in which I've gained the least experience.
"sit back, relax, and watch" is what bothers me. This approach is bound to lead the co-pilot into a "I give up" mode and he or she will go from being part of the crew to just a pax in the RHS, learning nothing but the fact that they are incapable of doing what they have been trained for. Perhaps it makes you feel better knowing that you are in full controll of things, but in the case that you feel they are not capable of doing their job properly, the more appropriate approach to the problem would be to give the CP a call and make him or her aware that so and so is in need of more training and if the situation is so bad that you'd rather fly alone, cancel the flight. This is of course an extreme situation, but you should not accept to fly a multi crew plane in a single pilot operation.
I have about a 1000 hours of which 650 is in commercial TP's and I consider myself still in training. Even though I was checked out a little more than a year ago. And I will still be in training a year from now. The training never stops and therefore asking your crewmember to step aside in other than extreme cases will achieve nothing positive in the big picture.
The best captains I've flown with have when I've shown phases or sides that have been below standards, given me a little more responsibility, let me do another leg as PF and so on to give me a chance to rise to the challange. These are the flights that have made me a better pilot and subsequently on the next flight, I've been able to produce a higher standard. This is perhaps the better way to go about the problem than to just cut them out of the loop
.
/LnS