Nothing illegal or particularly surprising was revealed in the 2016 emails; the only illegal act involved here was (presumably) Russian hackers committing several federal felonies in order to get access to those emails.
Yes, they were embarrassing, but any political organization, or indeed any organization at all, will have mundane communications that seem shocking to an outsider. The RNC almost certainly had more shit talking about their candidate in their emails. Assange had access to those RNC emails, and chose not to release them, even though they'd be, if anything, more interesting than the DNC ones. Assange is no information freedom fighter; he amounts to a political operative who collaborates with criminals to ratfuck candidate he doesn't like, for whatever reason.
He has a similar history with e.g. refusals to release Russian state secrets. Why should we celebrate a hypocrite who is motivated primarily by petty personal feuds?