I may be misinterpretting the parent, but I don't think he was disagreeing with the assessment that a 1-10MM/yr business is a lifestyle business, but more that a 10-100MM/yr business is "no man's land".
Also, from my experience, founders do actively promise not to go down the slow path. It isn't some implicit agreement. When you pitch to investors usually 2 of the most common questions are "What is your growth plan?" and "What are your exits routes?". If you project to be a 10MM/yr business in 5 years, VCs probably won't pull the trigger, and if you told them 100MM/yr in 5 years you can understand why a VC would maybe think you aren't moving fast enough if you're an order of magnitude off that number.
As for YC companies, as I've heard many time on HN when there is a post about an investment or an exit, it's all about the terms and where the company is, however it seems from reading his essays like PG's advice is to be aggressive about taking money when you can get it, so that may permeate down to the YC companies so you could be right.
Also, from my experience, founders do actively promise not to go down the slow path. It isn't some implicit agreement. When you pitch to investors usually 2 of the most common questions are "What is your growth plan?" and "What are your exits routes?". If you project to be a 10MM/yr business in 5 years, VCs probably won't pull the trigger, and if you told them 100MM/yr in 5 years you can understand why a VC would maybe think you aren't moving fast enough if you're an order of magnitude off that number.
As for YC companies, as I've heard many time on HN when there is a post about an investment or an exit, it's all about the terms and where the company is, however it seems from reading his essays like PG's advice is to be aggressive about taking money when you can get it, so that may permeate down to the YC companies so you could be right.