The Smurf DDoS attack takes its name from the malware used to execute the attack. Smurf malware was created by an adolescent, Dan Moschuk (1997). First, he shared the original software just with his friends, but the smurf.c was crashing Internet Relay Chat (IRC) servers a bit later.
For Dan, this was an achievement. For the world, it was another threat to be worried about.
The Smurf malware proved to work, and that encouraged him to enhance it for being more harmful. And he got it. Years later, he released his Fraggle.c., a UDP version of the Smurf software.