This change makes sense. Joining a raid to do this is not "working as a group". You don't really work with people or communicate. You just have everyone run around randomly and kill as much as possible. You don't even see half or talk to the people. That was not the intent, and most people (including Blizz) realize that.
You will still be able to join groups of 5 or less to burn mobs down fast, and that will promote group play. Doing it in a "raid" does not really promote group play like an actual LFR raid does (where everyone is working together to kill the same boss).