One could easily argue,based on what you stated, that Morrigan was simply every man's fantasies given form. That she wasn't so much a well written character as an embodiment of what many men like. A fetish, if you like the term. So, in that way, I felt cheated because even in a fantasy fictional world that fantasy is beyond my grasp. So, Morrigan wasn't a compelling character because she was interesting. She was compelling because she was simply what people wanted her to be. A Mary Sue character if you'll forgive the slightly misused term. Beyond that male characters had a crazy woman and a man-whore. Not great choices when you look at it that way.
In Mass Effect 2, male characters had Miranda, Tali, or Jack. Or a poor man's Morrigan (and less interesting), an alien in a suit who you never see and might be a Predator type beast, and a tattooed psychotic shaved head killer. Great choices for your male characters there, too.
Better than the original KOTOR, I guess. You had Carth (for female Revan) and Bastila (for male Revan). And neither of them were all that great either.
Of course, we could nitpick all day if we wanted. They still are great games. The romance options may not be great, but at least they try. They are there to explore the world, and your characters, and even yourself, in a whole different way. Success may vary is all.