It probably does not make sense to stay lean when you need to scale. Scaling is a big effort that require a heck of resources. When a company decides to scale, it can no longer afford to make pivots. Yes, because there is a committment on the infrastructure which renders even small changes extremely expensive.
This means that when you decide to scale, you must do it right. And to do it right you need to have learned everything about your business.
So, I believe that Lean Startup has its own scope and it is a mistake to try to apply where it is not appropriate.