It's not "smearing" to use Zuckerberg's own words in a discussion of his character, and this is far from the only example of things he's done or said in the past 20 years that would lead a reasonable person to call into question his moral fiber.
It remains, however, a popular point of reference because:
1. It's fast and easy to read and digest.
2. The blunt language leaves little room for speculation about his feelings and intent at the time.
3. A lot of people understand that as Zuckerberg's wealth exploded, he surrounded himself with people (coaches, stylists, PR professionals, etc.) who are paid handsomely to rehabilitate and manage his image. Therefore, his pre-wealth behavior gives insight into who he really is.
It doesn’t though, no one is the same person they were 20 years ago and every young person is makes a ton of mistakes
> his pre-wealth behavior gives insight into who he really is
"No man ever steps in the same river twice, for it's not the same river and he's not the same man."
Not defending Zuck but it reflects a rigid mindset to assume that people cannot change.