Might not extradite for political crimes, but they straight up let CIA kidnap people from their soil. If Assange was returned to Sweden, he'd be let out on 'house arrest' and he'd just dissapear into the dark one night.
A country like Switzerland can afford to act a little bit more neutral because they are located in the middle of Europe, with no close enemy in sight, but when you share the same sea with the Russians things are different. Come to think of it even the Swiss had to renounce part of their famous banking secrecy when the American IRS came asking for questions.