How much of Jean/Logan is Jean just being a decent person and caring for someone that is hurt or needs support?
In some aspects it's like Logan's looking for something that isn't really there...and then Jean has a "need to be needed"
It's like a co-dependency thing rather than true love.
Same could be said for Scott/Emma. Scott was looking for someone to tell him he wasn't a bad guy after being merged with Apoc. His wife who knew what it was like to be bound to an evil being wasn't giving him any sort of reassurance. Emma knew what it was like to play the villain and knew Scott wasn't a bad guy...but thought "hey this could be fun"