The surrounding paragraph gives a bit more helpful context.

"A typical startup is built around a single product, and some theory that people will pay money for that product. This theory eventually become false, and the company goes away."

The link to towerrecordsmovie.com is suggesting that many single-product companies outlive their product's usefulness, such as Tower Records. Tower Records was a large seller of physical music media (CDs, Casettes, Vinyl) which went out of business in the mid-2000s.

The author is suggesting that since Fog Creek is not a single-product company that this does not apply to them.