Well not many serious texturists I know of use C&P. I can think of three on the top of my head. (Not gonna be calling out any names here.) But Still, those texturists have to go though a lot of work to make the head still seem natural.
Also, why should quality matter here? The only thing that separates C&P-ers from the rest of the arting field is that they don't have a "full" right to claim their art as theirs. Does that necessarily mean that their work is bad? No. But, just because some, or a majority of their work was made by hand; doesn't undermine the fact that a portion of it wasn't. Copy & pasting is persecuted for one reason, and that is the act of using something that you either couldn't wouldn't create. To me, its like admitting that you lack a certain care for your work. It's admitting that you lack either skill, dedication, or more likely than the above time. However, at the same time is also says that you still, as an artist, want your work to look good; and, aren't willing/able to put the work needed into your texture for the high quality that you want to create.
So yea, quality doesn't really matter in this case. I mean, no matter how you put it good is good. And will always be good. It's neither ethical, nor unethical. But C&P is just admitting that you're lazy in a sense. Which is why it's typically condemned.
But to me, It just doesn't really matter. Because we've all had bad days and nights where we've needed to rush. And on those days "lazy" just seemed like logic. So to take it from the C&P-ers perspective. It's not really something that should be that bad. But is it bad.