Well, given that "move fast and break nothing" does have that catchy je ne sais quois (at least to me) that makes a motto resonate, I'm assuming it is controversial in some way. Maybe not in whether it's a good idea but in whether it's even possible. I think it is a pretty controversial/shocking claim to say that you can move with startup efficiency without sacrificing the reliability that slow-moving large corporations with pointy-haired bosses seek. If the industry readily accepted that claim, the industry would look a lot different from how it does now.