"If you build it they will come" doesn't quite work on the internet. Except maybe if your product is extraordinary. But before the internet, when it's just you in your parents' basement? Then you need a real marketing channel otherwise you stand no chance. Even the Id guys had to write shareware games for an established distributor before they figured out how to do the shareware thing.
Today you can bootstrap a business worth millions based on a $8 a month VPS. As far as I can tell this hasn't been true in any other part of history or in any other field. There is still so much low-hanging fruit in software - it's crazy.