Pink diamond didn't like pink pearl, pearl or spinel because they are MADE for her, made to please her, made to not have independent thought. The same single minded thinking that the diamonds expect from her. She liked Greg because he understand what it's like to live under strict rules, and want to break rules like her
Pink is treated as lesser than the other diamonds. So in turn she doesn't feel worthy of affection other than it's a toy for her to use, because that's how the other gems are toward her. Just her toys, especially Spinel and look how that turned out
Rose is also stated to have been toying with other humans, as Pearl said "just a phase". Not realizing she's in the same boat














