To approve a medicine, the FDA requires five criteria to be fulfilled...marijuana legalization via ballot amendments or legislative bills does not meet any of the FDA requirements.
Smoking dope, getting high and saying I feel better is not a criteria for medicine.
Links
[1] https://www.washingtonpost.com/news/in-theory/wp/2016/04/29/5-reasons-marijuana-is-not-medicine/
[2] http://rethinkpot.org/tags/medicine
[3] http://rethinkpot.org/tags/madras
[4] http://rethinkpot.org/tags/fda