@ilikepie I have two equally-good, possibly-related explanations to offer you:
1. If your fantasy nobility setting doesn't involve love, betrayal, and dramatic demises, you're not using it to its full potential.
2. Dark, painful backstories are near and dear to the hearts of many women because we were drawn to Tales of Dramatic Woe when we were little girls and it's hard to grow out of that entirely. (If your princess tea parties didn't involve secret plots to poison the queen, dramatic revelations of parentage, evil sorceresses, or anything like that, then you weren't any little girl I knew. My sister and I played out our courtly intrigues with Megablox dragons. Good times, good times.)