This is crucial. From the article:

>As a result, we internalized a deep-seated attachment to an unblemished white image of Greek and Roman art. We became, to use David Bachelor’s term, chromo­phobes. It is this accidental association between Greek and Roman art and pristine white marble, we are told, that accounts for the displeasure we feel when we see the statues restored to color.

And there's indeed been quite a bit of push-back since the story first broke. Unspoken is the reason. Primacy bias is probably a part of it, but what really accounts for the intensity of the attachment to the idea of white marble finishes? I'm sure you can imagine.

>Bond told me that she’d been moved to write her essays when a racist group, Identity Evropa, started putting up posters on college campuses, including Iowa’s, that presented classical white marble statues as emblems of white nationalism. After the publication of her essays, she received a stream of hate messages online. She is not the only classicist who has been targeted by the so-called alt-right. Some white supremacists have been drawn to classical studies out of a desire to affirm what they imagine to be an unblemished lineage of white Western culture extending back to ancient Greece. When they are told that their understanding of classical history is flawed, they often get testy.

https://archive.is/qTreQ#selection-1695.0-1695.693

So, yes, it was important to categorically falsify the notion that the statues, frescoes, etc., were unpainted. Anything that left it open would have been something for the worst sorts of people to latch onto. Now that that's out of the way, possibly even more accurate explanations can be given the time of day, instead of being stuck having to hash out, "Oh, but were they even colored at all?"