My opinion (student pilot, currently PPL IR) is that the FDs should be used in order to improve accurracy.
I'm thinking I should bank 17° right and pitch 3.5° up, my FD tells me 18° right and 4° up, ok then, I'll follow it.
If it tells me 15° left, and if I'm sure of my 17° right, I will have no moral or ethics problem at all with shutting it off. Or even more shocking for my instructors, no problem at all flying opposite the FD. Even more so when the reason why the FD is not aligned with my idea is known. E.G I'm in heading or nav mode but I am willingly taking a turn for weather avoidance. In this case I know the FD directs me into an unwanted situation : **** it, I'll do what I know is better.
The fact that professional pilots would follow the FDs instruction without thinking twice, or even worse that instructors would train people to do so, frightens me.