If you ask investors to rank in order of importance the quality of the team, the quality of the product and the size of the market for a young startup, most will put the team first.
That's why I really like the way Marc Andreessen defends the choice to put the market first in the value chain.
In this 2007 post, he argues that the market is the most important factor for success, or failure, for a startup.
Beyond a posture that can be considered politically incorrect by not positioning the human being as the first factor of success, his reasoning is to say that a quality market will systematically "pull" the right product from a startup. Like an irresistible physical force, a well-selected market will necessarily attract the first viable product given to it. Even if it's not great.
Conversely, for Andreessen, having the best product in the world and a killer team will not change anything in a bad market. The startup will be doomed to failure.
He expands his argument in this post still considered today as a classic.
Funny detail : Andreesseen mentions micropayments and videoconferencing services as examples of markets where many startups have failed. While the background of the article has not aged a bit, things have changed significantly since 2007 with regard to these two markets!
Do whatever is required to get to product/market fit. Including changing out people, rewriting your product, moving into a different market, telling customers no when you don't want to, telling customers yes when you don't want to, raising that fourth round of highly dilutive venture capital -- whatever is required.
When you get right down to it, you can ignore almost everything else.
I'm not suggesting that you do ignore everything else -- just that judging from what I've seen in successful startups, you can.