Never heard of if being any type of "fad". If I lost my current pair I wouldn't hesitate one second to purchase another set.
I wasn't calling goggles in general a fad, but simply asking if the I/Os were as good as they are hyped up to be (it sounds like they are). You can't tell me that Oakley A Frames weren't a fad! Everybody and their mom used to own a pair of those just because of the almighty Shaun White. To each their own really.