It's not like they were doing much with her anyway, aside from the same tiresome psychic rape they've already used in TNG episodes.
You know what Marina Sirtis was really good in, though? Gargoyles. She was the lead villain Demona, and her only slightly disguised contempt for the human race and her ex was a beautiful thing. Marina can really act... when she's given good material. Star Trek relegated her to window dressing (and I blame Berman for that).