For her to be so popular, she must be truly special... or the other love interests available in the game are really bad...
As others have said, she is optional, but I think that's also a larger factor in that no matter what route your character plays out, Artemis will also always been central to the story plot, where some of the side girls can be mostly ignored.
I'm pretty superficial with some of it, though. I love June, especially with the red hair, but seeing her in flashbacks was a bit of a boner killer for me. Kindra is goofy and fun, but I see her more as good friend material, nothing romantic. Artemis.. eh.. I dunno. Zelda is really the weirdo standout for me. She's pale, blonde, and exactly what I'm not usually into in women. But on the flipside, I like the vampire aspect to her, and that she's got a good brain in her head. If I could tag-team June and Zelda I absolutely would. Reina's honestly pretty solid, too, but it does seem like a fair number of the sorority gals are a bit mental. That's not a complaint, that seems fairly realistic on the face of things. Just not sure how it'll all play out. Katy's sister is probably next on my list. All the cuteness of Katy without the face tattoo, and a stick so far up her ass I can use it to steer the boat. Bring it on!