People have been requesting difficult content for light parties for quite a while now - this content is supposed to fullfill that request.

One thing that makes Savage so difficult is that you need 7 more people to attempt it - static scheduldes are one of the things that really complicate Savage. So we got Criterion Dungeons for those who want that challenge, but dont want to work around 8 different scheduldes and reducing that to 4 instead.

I agree that some "middle ground" content would be nice, too - but at least I was never under the impression that Criterion was supposed to fill that niche; it was supposed to be Savage but for light parties.