Bootstrapping requires a rare breed of founder who is financially secure enough (or frugal enough) to manage life on a reduced salary, capable of building useful products on a budget, and willing to risk the missed opportunity cost of a cushy Big Co position. In my experience, the hardest thing to master is the actual building - plenty of people are bootstrapping "theoretically useful" inventions in basements/garages/etc, that don't solve actual problems. Such people can really benefit from VC oversight and business acumen.