I think it would be nice if it were revealed that Pink Diamond was full of love and warmth.
However, that would not mean that started or even supported the rebellion. Honestly, I’m not that fond of the idea that a loving Pink Diamond would value the well-being of Earth beings over that of gems. That the only way she could express love would be going against Homeworld’s ways.
Pink Diamond might have started the zoo because she wanted to preserve a few humans. But would that mean that she values them over gems? I have a small headcanon (with admittedly little to no evidence) that Pink Diamond started the zoo because she wanted to use it to benefit other gems. That the zoo was designed so that gems could relax by watching humans in their “native” environment, but not because Pink Diamond valued humans themselves. Don’t forget, Holly Blue Agate told Sapphire that it took awhile to figure out how to properly treat humans. So it’s likely that Pink Diamond wasn’t thinking about the well-being of the humans she brought to the zoo.
While it might seem strange for such a work oriented society to have a place where gems can just relax, don’t forget that Pearl describes the lunar sea spire as an “oasis for gems on Earth” and showed Steven an image of gems on Earth, who really didn’t seem to be doing much of anything, other than enjoying themselves. Also, the gems who have expressed disdain and/or confusion for gems doing other than their assigned purpose are ones that have followed Yellow Diamond, whether it was because they were made for her or because they were assigned to her later. So maybe Homeworld itself used to be more relaxed, and changed after Pink Diamond’s death. Or maybe places like the lunar sea spire still exist on Homeworld, and it is only Yellow Diamond that values a gem by her work.
And it would also be terrifying if Pink Diamond supported the shattering of off-colors because she loved them. If Pink Diamond genuinely thought that being an off color was so utterly dreadful that shattering them was showing them mercy. I just want a Pink Diamond who is both full of love yet incredibly cruel.