Miss Adebayo visited and said something about grief, something nice-sounding and facile: Grief was the celebration of love, those who could feel real grief were lucky to have loved. —Chimamanda Ngozi Adichie, Half of a Yellow Sun
“Joker” takes off from a facile premise and descends into incoherent political trolling as a result of scattershot plotting and antics—its director, Todd Phillips, appears not to see what he’s doing. —The New York Times
Unless you read a lot into definition 4 of Webster's, the app dictionary, or even the word 'shallow,' gives a result much more accurate to how I've seen the word actually used. With more than a century and a half since the dictionary was first published, seems like plenty of time for a shift in meaning to happen.