Of course he has done wrong, but the fact why people are standing up for him is he did not do it while being in the US. It is one thing if the US asks for extradition of a criminal who committed the crime in the US, but an entirely different thing if the criminal committed the crime in another country - and that doesn't even answer the question if what the criminal did is actually a crime in that country.
It's already a legal stretch to arrest and punish pedophiles who fly out to Asia to rape children (because enforcing the laws against child rape should be something for the destination countries!), but the Dotcom and Assange sagas should not result in extradition.