Let's take Miss-Too-Much-Lilac-Eyeshadow. Jaina, being not only beautiful, intelligent, and an immensely powerful human mage, has attracted the eye of more than one suitor. First, and the tender age of fifteen, a young[er] Prince Kael'thas Sunstrider desired Jaina for his own. Now, all uncomfortable social situations aside, how would that have changed Kael'thas? Remember that the wayward Prince of the Elves went into the Outlands and ended up teaming up with Kil'Jaeden instead of saving his people. You know how it goes. But what if Jaina had been there for him? Would he still have gone nuts?
What about our dear Prince Arthas? Instead of publicly breaking up with him prior to the Culling of Stratholme, what if she had stayed? Do you think she could have calmed his tumultuous heart? Made him, well, not so Lich King-y? Lastly, let's not forget the Stormrage x Whisperwind thing. What if Tyrande has chosen Illidan? Would he still have risked so much to try and impress her? To show her what a great hero he was? Maybe he wouldn't be brooding in a derelict temple in the Outlands?
Please keep in mind that I am in no way trying to vilify these women. They're all amazingly strong characters who have stood and faced great peril and responsibility. I applaud them all for thinking for themselves, but I always had to wonder: what's love got to do with it?