As someone who has studied both humanities and "hard" subjects, I'd definitely say that I respect really good researchers in the humanities just as much as I would a Fields medalist, but there's a much lower bar and there's a lot of shoddy research being done (as well as really bad students who just coast by somehow, something which is much harder to do in math-heavy subjects).

Then there's also the problem that there's not even a clear consensus on what great research is in a "soft" field. I might find someone highly accomplished, but someone else might think the opposite. With maths, either someone proves a theorem or they don't, there's almost no middle ground (Mochizuki notwithstanding).