i don't think there is too much tension between "lean" and focusing on product quality before growth. the best way to improve the product is to get people using it and use their feedback to improve it. that's what lean is all about.

airbnb's 1000 days are mentioned in the article. it is not like they were just coding in their living room during that time. they had a product out, and they were flying to NY to talk to every possible host, improving the listings, and so on -- learning what made the product awesome. it was probably tempting at the time to work on getting more hosts on the platform, or to optimize the number of bookings, and other growth stuff. that's what Sam is cautioning against.