I personally don't dislike past gen games, for me it's the concept of opportunity cost (or rather how I perceive it to be, coming from a position completely outside the industry without any insight and I could be wrong but..):
Presumably companies like Microsoft/Sony have finite resources, so there's this perception that any resources diverted to stuff like BC are resources diverted away from making next-gen games.
In reality, it may be the case that the people working on these past-gen game enhancements never had anything to do with next-gen development endeavors (and were hired separately from the new game makers specifically for this stuff, or they are hardware dudes who have a bit of downtime now that the new consoles are released) and so there is no opportunity cost. I was against the idea at first but seeing stuff like Yakuza 6 at 60fps and Battlefield 4 at 120fps... I can't really see any downsides.