In his discussion with Sarah Lacy on stage for PandoMonthly tonight, Facebook co-founder Dustin Moskovitz said that Y Combinator’s “no idea” round for entrepreneurs is “really wrong.”

“It’s not just bad for that person,” he said, “it’s really bad for the ecosystem.”

People who decide first that they want to be an entrepreneur and then go looking for an idea are getting it the wrong way around, he said. “The only reason you should be an entrepreneur is because that’s the only way the idea will come into the world,” he said.

A lot of great people are wasting their time and talent by pursuing “something that doesn’t exist yet,” instead of joining bigger projects that already have proven ideas.

“The 100th engineer at Facebook did way better than the vast majority of entrepreneurs in the Valley,” he said. And more importantly, they “had more impact”.