I can list a hundred tech companies that wouldn't have been successful / acquired had they not raised money. You couldn't really bootstrap Twitter. Or most medical device companies.

I have a friend bootstrapping a company right now. He is growing organically, and is cash flow positive. He'll likely be acquired in 4 years for about $20M. That's awesome. But if he would have raised just $3M, he could have built his product in 18 months instead of 5 years.

In the end, he'll have the satisfaction of having bootstrapped. But from a purely financial perspective, I think he would have been better off raising money and exiting (or being even more profitable) faster.