Dire Bare
Legend
For examples, Angels and Unicorns. If you ask 100 average people on the street if those are good, neutral, or evil, the vast majority will say good.
It is certainly true that unicorns are typically seen as "good" creatures. But in the long history of D&D monster stats, we've had more examples of neutral or evil unicorn variants than than the single example of the "base" unicorn stats.
WotC simply decided, "Why make unicorns inherently good, when we'll eventually turn around and publish the black unicorn and blood unicorn (etc) stats? Let's just make them more neutral to begin with, than specific examples of unicorns can be good and have a thing for virgins, and others can be unaligned or neutral."
Same could be said of dragons, couatl and many other traditionally good creatures. WotC did a lot of research into HOW most people actually played D&D. And they found that most players did not need stats for good aligned opponents, but plenty of evil and neutral exceptions and variants were created so players could fight metallic dragons and unicorns.
The keywords here is "most people" and not "all players". Obviously there are those who disagree with WotC's new game design and resent the various changes to the implied "core" D&D setting . . . but WotC is banking on those folks being in the minority and that the changes will appeal to the majority and help reel in new players. They could be wrong, of course, but WotC didn't make these choices in a vacuum, they did a lot of research. And while we certainly have some folks loudly proclaiming sacrilige, we seem to have just as many (if not more) that either don't care about the changes or actually like them. I'm in that group.