Zuckerberg was 19 when he made the dumb fucks comment. [2004] I'm not agreeing or disagreeing with your point, just saying that this incident took place earlier than you think it did.
The decade immediately after you’re teens is a time period with a lot of change. Many people find career paths, spouses, and have children. Also worth considering is that FB is a much different company — structure-wise — than when it was just a social media site servicing Harvard students.
Sure, it's possible that he's stopped having a callous disregard for other people's privacy in those ten years, but all of his actions seem to demonstrate otherwise.