I strongly disagree. That's part of it yes, but that's not the entirety of it. A story needs characters, not just settings and events. Ask any fan who are the first characters that come to their mind when they think of Starcraft, I'd bet you anything that Kerrigan is among the first 5 named. For better or for worst, Kerrigan is a main part of that story. She can't just be another brain monster. Would you replace wolverine in the X-Men with just another mutant? "Oh but the story is not about his personal vendetta, it's about the struggle of being different". Sure it is, but the vast majority of fans want Wolverine in X-men and that's just how it is.
Argue all you want, she will still be on the box cover.
Can you point me to a good story that's strictly about factions/organizations and their struggles? A completely impersonal story but yet still a good story? I don't know any. In my mind, it's close to impossible to make such a story without it sounding like a dry history lesson. Imagine Game of Thrones/ASOIAF but no one has names and everyone is just a generic medieval person. "Princess X got back-stabbed by rogue assassin of faction Y at King X wedding which started the fifth war of...". That sounds just horrible to me but if that's your thing, consider yourself in the minority.I don't understand you people. Why do you want Kerry to be the main character, rather than the competing factions with their distinct morals? That's not what Starcraft was about!