I understand that if you do not have time on your own , then you do not grieve for what you had, and EVERYONE has something to grieve at the end of a relationship.

What happens then is they take that non closure into the next relationship and they can be sure it will not last. They may grieve then and if they dont, then on it goes.

BUT one day they HAVE to face it. You have to grieve. They are just trailing a whole load of crap with them.