Really? You're suggesting that psychologists (to arbitrarily pick a softer science) would deny physicists (to arbitrarily pick a harder science) should reproduce their studies where possible?
That seems remarkable to me, perhaps I've missed these discussions. Can you provide evidence that this is a pervasive movement in some sciences, rather than the opinion of a few?
"Many" is a trigger weasel word, of course, and needs backing up.
My interpretation -- perhaps incorrect -- is that you feel the softer sciences are wilfully undermining the quality of harder sciences. I very much doubt this is the case. Some philosophers of science and some softer science key influencers may introduce difficult and challenging questions about the appropriateness and usefulness of some research methodologies (as are people in this thread) but I doubt they'd make the blanket assertion you're suggesting.