No, from a scientific point of view there are few/no situations where one would want to do a blind test! Blind tests are often very difficult to set up without flaws, flaws which can end up with variables other than the desired devices/variables being tested, not to mention that even a flawless blind test would still be subject to potential statistical aberrations. Scientifically, blind tests are therefore never absolutely conclusive, they provide supporting evidence rather than proof. If we've got two devices, A & B and want to determine if there is an audible difference, the first thing I personally would probably do is conduct a null test. If they null, end of discussion, we have absolute proof there is no difference period, let alone an audible difference. If they don't null, what we are left with is the difference: If that difference is below say -100dB we can safely say it's inaudible, as it will be several/many times below the threshold of audibility. If that difference is higher, it might be audible, depending on how much higher and where in the frequency spectrum the differences are. In which case, we might be forced to use a blind test because despite the fact they have potential flaws, they have far fewer flaws than the remaining alternatives (sighted tests or anecdotal evidence for example).
This scientific approach is of course invalid when evaluating a musician, we take it as given that there will always be differences (within the range of audibility) between musicians, even a musician deliberately trying to copy another musician and even between different performances by the same musician. When evaluating a musician we are not therefore trying to find out if there are any differences but identifying what the differences are and making qualitative judgements about them (relative to some abstract/subjective concept).
G