With irony-sensors switched off, I could point out that it is already there, since 'simple' is a noun as well as an adjective, with the plural form 'simples'. It is used in herbal medicine to describe a remedy with just one ingredient (thanks to Judy Delin's encyclopedic mind for that).
Apparently Aleksandr's usage is catching on - someone used it in an email to me the other day, hence this geekish hunt for origins.
It turns out that as with so much, Shakespeare was there first. This is Jacques in As You Like It:
'I have neither the scholar's melancholy, which is emulation; nor the musician's, which is fantastical; nor the courtier's, which is proud; nor the soldier's, which is ambitious; nor the lawyer's, which is politic; nor the lady's, which is nice; nor the lover's, which is all these; but it is a melancholy of mine own, compounded of many simples, extracted from many objects, and, indeed, the sundry contemplation of my travels; in which my often rumination wraps me in a most humorous sadness.'Act 4, Scene 1.I'm quoting it to get in the wonderful 'scholar's melancholy, which is emulation'. They had the Research Excellence Framework in the old days too it seems.