The reality is that both engineers and sales have their own respective forms of myopia. Engineers often bias towards elegant code and architecture, salespeople bias towards whatever the last sales lead said on the phone. Both have some value, but neither one will unlock a massively scalable market. To do so you need some vision beyond what the sales lead is saying on the phone or what is easy to design elegantly. Not just that, but you also need rapid iteration and not to fall so in love with your early thinking that you can't effectively capture new insight along the way.