"Snapchat is not a bunch of features," Spiegel said on Tuesday at the Code Conference in Rancho Palos Verdes, California. "It has an underlying philosophy that runs counter to traditional social media."
Spiegel characterized Facebook's core mission as convincing people to build lots of shallow "friend" relationships, then "having people compete online for attention." When people "realize that competing with their friends for likes" is not great, they'll turn to Snapchat, which focuses on building connections with fewer people but actual friends.
"Fundamentally, they're having a hard time changing the DNA of their company," he said.
He also said that Snap was somewhat flattered by the imitation, because a designer feels a sense of "triumph" if the only thing a competitor can do is copy a product precisely.
"We would really appreciate it if they copied our data protection practices as well," he added.
Spiegel also noted that Snap built its entire business around the idea of minimizing data collection -- Snapchat's original core feature was trading pictures that disappeared -- and said he was gratified that the entire industry is now being forced to move this way by increasingly strict privacy laws like the EU's General Data Protection Regulation (GDPR).
He also emphasized that being public really forced the company to focus on its values and long-term decisions, even when that might hurt the stock price in the short-term. The company has lost 38 percent of its value since its stock market debut last year.
"The important thing is building that muscle of not putting numbers before doing the right thing for people using our service," he said. "It requires a bit more grit than being a private company."