In “Chosen One” plots, the protagonist has some born-in virtue or heritage that makes her the One Person Who Can Save Us. This is extraordinarily common in fantasy fiction, though it appears in SF as well (e.g. Jupiter Rising). In “Power of Love” plots, love has a spiritual, emotional, or mystical power that can directly affect the world. This is rampant in Hollywood (e.g. Interstellar); possibly less so in books, but that may be my reading tastes.
I see these two plot components — Power of Love and Chosen One — as “the same thing,” because they represent two facets of the same basic story choice. And that choice is pandering.
The common characteristic here is that success comes through no skill, training, or expertise. You could be revealed as the Descendent of the Hero! (You can worry about your training montage after that.) Maybe you love your Cylon enough to make a mixed-species baby possible! This allows the you, the reader, to more easily put yourself in the place of the hero — but it’s a cheap identification. Forget interesting characters, forget engaging stories, just make the hero able to succeed via things the reader could do.
This is why it’s pandering: it’s a lowest-common-denominator viewpoint. Who cares about education and expertise, if all you need is love? And this is also why it’s more common in movies than in books: because movies want to reach a wider audience, and make them leave the theater feeling proud and justified, as if they could’ve saved the world.
There are ways to write good plots with both of these elements. For example, I forgive Harry Potter a great deal for its ability to make a Power of Love plot work intelligently. But personally, I am tired of stories where Expertise Isn’t Necessary.
Edit: Note that pretty much any “instinct and intuition are correct, all the experts and scientists are wrong” storyline also falls under Power Of Love plot. Exact same thing, different flavor text.