Since when is it possible to CMD-Q Finder?

I am on OSX 10.10.1. As of very recently (can't be more than a couple of days, else I would've noticed it sooner I think), I am able to quit the Finder by hitting ⌘-Q, which will quit the Finder app, not only close the window. There is also a Quit Finder menu entry, I don't know if that was there before. I asked someone who also uses Yosemite and as expected, they can't do it.

The question is: Why is this suddenly possible, has anyone else experienced it and how can I revert this change?