[jon2512chua]

Another problem is that when developers decide to do their own startup, the only domain they really understand is software development.

I don't believe this to be true - most, if not all, developers have hobbies and interests. For example, I'm into photography, so I would much rather build a photography software that I would enjoy using rather than something to solve a carpenter's problem (just an example) that I don't really care about.

For me at least I find that the benefits for this is two-fold: one, like the author said, so that I can be my own critic as I possess the domain knowledge, and secondly, I'll be much more passionate about working on something that I care deeply about.