I think that what psychology and others are is actually "hard" science as noted above.
That is the problem isn't that they aren't being conducted with scientific rigour; the problem is that it is hard to do it well. Chemicals tend to behave themselves and stay in their test tube and behave rather predictably. The chemicals of psychology are anything but well behaved.
The critisms calling psychology a "soft" science may be more because it is in fact a "hard" (as in difficult) science
.