purpled doesn't want the revival book to bring someone back
this could very well change as more of his side of the story is revealed, but as of what we know right now, purpled has no use for the revival book. he himself is on three lives, and when it comes to other people he cares about, there are very few. his relationship with ponk (2 lives) and hannah (3 lives) has been strained since the red banquet, and boomer (3 lives) is no longer dead. due to purpled's self-isolation, he has very little when it comes to relationships.
the book wasn't about its use. it was about the message. purpled knows about the visits, and has known for probably more than three months, as it can be assumed that charlie told purpled about them before quackity gave him the "trust no one" lesson. which means that he knows how hard quackity's been working to get that book, and how much of it has ended up defining him as a person and his actions. as he himself states, he's still furious at quackity's actions after the banquet, and the destruction of his ufo, his legacy. his first attempt to get back at quackity's legacy fails, as he's unable to gain political power and usurp him. he doesn't want to take the book so he can use it himself. he wants to take the book so quackity knows how it feels to lose something you've worked so hard for.
that's why he stops asking for the book when he pushes slime into lava, and leaves without any further fanfare. he realized that he didn't need the book to get rid of quackity's legacy. all he needed to do was take away slimecicle, and he could achieve the same effect, but worse. he's made quackity feel what he felt when he saw his ufo get destroyed right in front of his eyes. he's continued the cycle of revenge, just like quackity once preached.