If someone does something easily, or shows ease, it is described as facile in a good way, but if someone takes the easy way out and shows a lack of thought or care, it is facile in a bad way.
While it is a lovely sounding French word, facile is both a compliment and an insult depending on how it's used. Something that shows ready skill is facile, such as being facile with text messaging. But if something is too simple and superficial, or shows little care, it can also be called facile. "Being too cowardly to tell the truth and admit he didn't do it, he used the facile and sarcastic excuse that the dog ate his homework."