I think it would be very nice if SQUAD decided to implement some sort of story mode in the later versions. It maybe shouldn't be something compulsory, but rather maybe make the world have a main quest, that you can complete at your own pace (unless there is a special mission.) The story could look like this:
First, you have to "compete" to gain dominance in space. This could work by having time limits in which you should reach your goal. (A little like the space race)
Later on, you might have an anomaly or something and you should set up a base for research, or something like that. (Maybe have it so that the player cannot do this mission with low tech for various reasons)
Than, there could be some doomsday scenario where you must save kerbalkind or something like that.
Finally, here could be multiple endings to the story mode, depending on the player's milestones, tech and decisions.
What are your thoughts?