I agree. Sometimes it is true that it is more difficult to do certain things in a smaller scale, but sometimes it is not.
I suspect that it is actually easier to do a valk in 1/100 than in 1/60. Details aside, being smaller means (1) pros: lighter weight so gravity won't screw you easily; (2) cons: some parts may be too small to handle pressures (fragile).
Given years of engineering, I believe we worry more about (1) than (2) nowadays. We still see (1) pretty often (floppiness), while (2) are more often mistakes (VF-1 version 2 broken shoulders).