You don’t create a firm by creating a firm; nor do you do science by doing science. I read this as Paul Graham's point that startups should not "play house".

You don’t create a firm by creating a firm; nor do you do science by doing science. I read this as Paul Graham's point that startups should not "play house". They're both saying that creating a company isn't about getting funding, hiring people, having a website and a logo, etc. It's about making something that people want, which can start in any number of ways that might not look like a company.