"an intense and widely shared enthusiasm for something ..."

Yes.

"... esp. one that is short-lived and without basis in the object's qualities"

No. I explained why.

Also, Apple did not do it first. Google, for one, launched "flat" redesigns prior to iOS7.

Even if we're only counting recent times, Apple did not come out with it first, they followed Windows 8?

Yep, but that's how it works. A year ago, people were complaining that Apple sucks because iOS was still using skeuomorphs instead of flat design like Android and Windows 8. Now they've switched their style, and they suck because they invented flat design and everyone is just copying them.