Julian Assange, like everyone else with public influence, is fair game for criticism. There is absolutely nothing wrong per se with voicing criticisms of him. I've done it myself on several occasions. Everyone with a public platform should be subjected to critical scrutiny, including him.
But the notion that there's anything "brave" about criticizing Assange - easily one of the most hated people by western governments and establishment media outlets - is an embarrassing joke.
Attacking Assange is about the most conventional and power-pleasing acts in which one can engage. Virtually no act guarantees instant, automatic and widespread praise in elite circles the way that attacking Assange does.
That doesn't mean the criticisms are invalid or wrong. It doesn't mean they're illegitimate to express. But it's a ludicrous conceit to pretend that attacking him takes "courage".
Yes, some WikiLeaks supporters will go on Twitter and criticize those who attack Assange. That, too, is fair game. But being criticized on Twitter isn't indicative of bravery. It's inherent to expressing any political views of any kind. Defending Assange also subjects one to intense attacks. So what?
Whatever else is true, Julian Assange is one of the planet's most scorned and marginalized figures among western power factions. Criticizing him may be many things - including, at times, perfectly valid.
But one thing it is not is brave.