I think, within a certain threshold, it is definitely more financially responsible to bootstrap. Though, I agree with your point about Twitter, etc: if you're a seasoned developer/entrepreneur with a large scale idea that requires serious capital to get off the ground, you can't bootstrap. But for something that is effective at a small scale and can be built from the ground up, the timeline only shifts a small amount (so long as you pursue all marketing avenues available).

I'm assuming that your friend evaluated the risks of fundraising and made a reasoned choice. I don't think it is fair to reason about his venture in hindsight.