Is Starcraft grimdark?: Darker than expected RTS storytelling

This essay will contain spoilers for Starcraft, Brood War, and Starcraft II.

    Already, I can hear some of you sniggering in the background. Starcraft? Grimdark? We're talking about Blizzard's other successful real-time strategy series, right? The one with the little cartoon space marines, aliens, and space elves, right? The one that isn't Warhammer 40K but is similar enough that at least one of the designers played it before the franchise moved in a different direction. Why y...