Without a doubt, diversity can improve the newspaper quality by putting ears, eyes, and brains inside the newsroom that understand the world outside. So, how do you increase diversity? You recruit for it and you train for it. But that effort isn't always painless. It's predictable that when a minority is hired or promoted that someone on staff will suspect that a diversity calculator in the backroom made the personnel decision, not a human being who considered only merit.
So, diversity provides valuable diverse views which lead to improved reporting, but nonetheless looking for diversity is the opposite of considering people on the basis of merit?
This is ridiculous. Look, I'm comfortable with debates on the intrinsic value of diversity when it, say, comes to recruiting students or something similar [Personally, I think there are a variety of reasons aside from the correction of historical injustice why there is value in diversity, but that's a separate debate]. However, diversity of backgrounds on the news staff of a major metro paper clearly isn't just about obtaining diversity for its own sake. Diversity of background isn't simply, or even necessarily mostly, equivalent to racial or ethnic diversity. But, a major newspaper has to report on a variety of racial/ethnic/other communities. The point of diversity in these situations isn't simply to meet some sort of easy racial quota, it's to make sure that the reporters you have on staff can capably address a variety of issues.