Maybe it’s a lot to do with your influences and how you view a portrait, too.
This, for example I think of as a great portrait, and so I would probably be influenced by it when deciding what I think is a great portrait photograph.
Of the two footflaps posted I really like the first. I and agree that it tells a story and is compelling, yet I also like the colours more than the second; maybe it’s over exposure on the face, maybe I’d darken it a little/increase the blacks/saturation?
It’s probably a good comparison with music. Some people prefer punk bootleg recorded on a dictaphone to a 5.1 92bit classical concert, despite the fact you can barely hear the music in the first.
Maybe we hear differently, maybe we see differently?