I think it's also possible that millennial's are realizing and recognizing the awful system that these chain restaurants perpetuate with servers making low wage

I think it's also possible that millennial's are realizing and recognizing the awful system that these chain restaurants perpetuate with servers making low wages, tipping, bad food, and high prices. Whereas my parents generation have always seen these as nice occasional dinners out, millennials see them as perpetuating a disadvantaged system.