It is a matter of consistency I think. Now we have object focused admin interfaces (eg. content, where you can set content options, review content, etc). Similarly for comments. And then we have task oriented admin interfaces, which means basically anything under admin
settings. Chx also pointed this out before, and it seemed that Drupal is going to the object based direction to utilize tabs (local tasks related to objects) instead of cluttering the menu. Now this change goes in the other direction.
A bit late, but here's the rationale. People didn't look for profiles under users -> configure as it was buried to deep. It is hard to notice that something has popped up that deep when you've just enabled the module. Making it a higher level item is handier to use. Also, IMO setting up profiles does not have a direct relation to the user objects. It's the filling in/editing of a single user's profile itself that I would classify under "users" rather than setting up the fields. I think many admins will think the same. Steven Wittens