The obvious rejoinder is that those decision points make the difference between a failed startup and a multi-billion dollar company.
As empiricists, though, it's worth asking if there are any real examples of companies exploiting hidden market opportunities thanks to a diversity of viewpoints. A lack of examples wouldn't be quite damning--maybe there's just not enough diversity at all to rise above the noise level--but it'd be a useful test of how valuable diversity actually can be.
This all stands apart from moral and ideological reasons to try to foster diversity, which are in my view more compelling but are understandably less effective when it comes to influencing decision makers.