Let me restate the common argument--there's this feeling that it's useful to measure people by the good they're doing for society, and that getting a PhD doing postmodern feminist readings of Christopher Marlowe is less useful to society than getting one doing Alzheimer's research or whatever.
I'll just say that it's worth considering whether an academic discipline's contributions may be difficult to notice but in fact substantial. Some academic disciplines like history or cultural anthropology must operate more qualitatively simply because the phenomena they aim to account for admit of no other approach, with the result that their intellectual products (especially when considered from the perspective of general society) will not often be as concrete as, say, a vaccine. But it'd be premature, of course, to dismiss a discipline just because its methods do not reach our desired level of formalization and its output is intangible.
If the issue you're raising is more narrowly one of your belief that within the scope of an _individual_'s wellbeing studying some subjects will leave them worse off than others, that's obviously true in at least financial dimensions, but that doesn't make a discipline a "fake subject".