I won't go that negative. Traditional medicine is still based on the limited scientific knowledge of the time. They observed that certain herbs have certain effects, so they crafted a theory on how it works, and it seems to hold true so they keep using it.

The difference is that now we have better tools/methods to determine what works.

With specific for TCM, the herbal medicine part was based on a book by the author trying and documenting its various effects, so in essence it's a very primitive form for scientific process. Can't exactly blame him for not knowing to account for placebo effects, controls, etc.