The term new wave came out of the late-1970s punk movement. At first, the label referred to punk-like music that came out of art schools rather than from the streets (Devo and Talking Heads are examples). At the same time, clubs and radio stations across the United States were afraid of punk music, so some punk groups started wearing ties and hats and calling themselves new wave. Even bands like The Ramones were sometimes billed as new wave. It was a safe way for a punk band to get gigs and radio play. There weren't many punk labels at the time, and to get national coverage, a band would have to sign on a new wave label such as IRS. New wave labels wanted a certain look and sound, and some bands changed to fit the bill. Punk fans would often refer to such bands as sell-outs. If punk and new wave were movements against the mainstream, "new wave" became a term sucked up by the mainstream.
As new wave took off, non-punk performers jumped on the bandwagon. Huey Lewis, Rick Springfield and Kim Carnes, for example, began to sport new wave outfits, pretending they were trendsetters.
As the new wave movement commercialized further and further, the wedge between new wave and punk widened.
To quote Polio Ferrari, "If punk symbolizes the Radical Left in music, new wave describes its wishy-washy liberals."
Or, in the oft-quoted words of L.A. music journalist Kickboy Face: "I have excellent news for the world. There is no such thing as new wave. It does not exist. It's a figment of a lame cunt's imagination. There was never any such thing as new wave. It was the polite thing to say when you were trying to explain you were not into the boring old rock 'n' roll but you didn't dare to say punk because you were afraid to get kicked out of the fucking party and they wouldn't give you coke anymore. There's new music, there's new underground sound, there's noise, there's punk, there's power pop, there's ska, there's rockabilly. But new wave doesn't mean shit."