It would expensive to require everyone involved in healthcare to know everything. Clearly, pharmacists have to know chemistry and pharmacology. And, with healthcare moving beyond re-setting of bones and such, and involving more and more drug therapy, we have been re-visiting the expectations of nurses. I think this is why we are seeing the bachelors degree required for nurses, instead of merely the associates degree, with the B.S. in Nursing involving chemistry and pharmacology courses appropriate to nurses. The investment required for a B.S. in Nursing generally pays good dividends in terms of a high-paying job.
I've seen plenty of nurses with B.S.'s and they were dumb asses. Oh yeah...they maybe were book smart...but couldn't assess a critically ill patient...if their life depended on it.
That said...I've seen quite a few Doctors that were dumb asses too!!
Personally....I believe a B.S. in Nursing is just a money making racket for colleges.