As a user since '97, I've often felt that this philosophy is entirely, well, backwards. I know how to read the release notes to learn of such changes and how to edit my personal init.el file to revert a setting if I don't like the new default. As long as no one takes away the option, the default doesn't really matter too much to me. But newcomers who might not yet be comfortable with editing their init.el files could really benefit from a more optimal out-of-box experience.
(And besides that, often the newer option is something that I've already moved on to, so making it the new default means I can now remove it from my init.el. I always enjoy when I discover that I can cut something from my init.el because it's now in base Emacs.)