Because we live in a civil society, if the police can't break into your house and take what evidence they want, and they won't accept evidence from anyone else who broken into you house what exactly does this serve?

If the only thing that is ok here is to leak stuff to the media stuff that usually cannot be collaborated, and often might actually be intentionally if not completely fabricated than at least edited to some extent you are advocating for mob rule and trial by public opinion.

If you believe "hacking and leaking is never wrong" because they're forms of speech, except when the state does it, you're not really a free speech absolutist.