"Baked in the cake" The newest most copied group of words. Someone somewhere groups a buncha words together and uses them. Before ya know it they're everywhere! Why do people so enjoy copycatting?

Good question.

Perhaps it's merely laziness, avoiding having to think too hard about the message to be conveyed, and how to convey it.

This slavish adoption of what may have started as clever metaphors good in their original text, so they become merely silly clichés, is particularly popular among politicians and business managers.

Sometimes it seems to be used to try to sound clever; to make the subject seem something perhaps just a bit too difficult for the listener so needs verbal help.  

A good example of the latter is ending a clear description of future actions, with "going forward", suggesting the speaker thinks the poor audience finds the future tense rather too much to follow. I recall one management presentation in which a speaker used "going forward" so often I gave up listening and mentally planned my forthcoming weekend instead.

I remember too, hearing of one audience member at one such waffle-fest, attracted colleagues' comments on his apparent, diligent note-taking. "Oh, I wasn't taking notes," he replied, "I was playing Cliché Bingo!"