Really this advice is born out of two things:<p>1. Many investors argue you should build your product in a narrow vertical that has the opportunity to turn into a much larger market. Given you start in a narrow vertical, you should aim to dominate that vertical (&#x27;Crossing The Chasm&#x27; makes a very coherent argument in favour of this).
2. Investors are aiming for 10-100x returns, and it&#x27;s hard to do that if you are not going to become the clear market leader.<p>Whether this leads to a better society is an interesting question.  One might argue that it makes your company more likely to be successful, and successful startups are job&#x2F;value creators which is better for society.