Sigh. I assume that 'Pink Diamond is literally the devil' trend is going to last a while.

Nevermind that she was more a figurehead than an actual leader for the other diamonds and that they treated her more like a child than a fellow equal diamond.

Did Pink acted immature? Definitely. Was there more simple and better solutions? Probably. But it's easy for outside observator with all the knowledge and insight of the future to say that NOW. Pink was a young diamond animated by pure and nobles intentions who took drastic and flawed mesures to make sure the Earth was going to be protected.

It's obvious she never thought the diamonds would actually care about her enough to lauch the corruption of Earth. That is probably her biggest flaw, underestimating how much she meant for the other diamonds. But she wasn't space hitler or complete dangerous fool. She was not perfect, like you and me. She is grey, not black, not white.

Umm, she did try to talk it with the other diamonds, remember the flashback in "Can't go back"? They dismissed her outright without giving her a chance to reply.