As a person I find Assange to be detestable
I haven't heard that one, actually. It's probably the same anti-intellectual assholes who will praise e.g. Gates or Zuckerberg, et al, for dropping out of college to do some 'real work' too, rather than staying in the ivory tower or whatever.
Let me help you off your high idealistic horse and say, that it could be the case, that people do not actually want to attack the topic, but care for it. It might be the case, that these people see Assange as a liability to actual whistleblowing and a useful idiot for more authoritarian players out there.
He centralised whistleblowing in the public's mind, whereas it should be decentralised by definition.