Why So Complicated?

We just filled in a form which involved listing the various medications that Ailz has to take- all of which have long, unEnglish and hard-to-spell names and I'm wondering why they can't have simple, user-friendly names which describe either what's in them or what they're supposed to do or both. For example (and this is simple and obvious because my medical knowledge goes thus far and no further) why do we say "aspirin" when we could say "willow bark pain pills"?

I know the answer, of course, It's about preserving the mystique- and so the power and revenue streams- of the medical profession and the drug companies.