And what is stopping those patriotic principled leakers from leaking things to just about anyone else? If the republican party e-mails were leaked for example I can guarantee you'd have a huge amount of journalists willing to publish them, even if in the theoretical wikileaks wouldn't do it.

At the end of the day the US is most likely the country with the highest amount of espionage in the world, maybe barring china, it's not like they can't do the same as some supposed FSB spy.

Expecting anyone to be impartial is a big mistake, especially when you can conveniently persecute and try to kill said person and with that pretty much force them to cease being being "impartial" at the very least in the public perception. Under the circumstances laid out all it takes to discredit someone as an "useful idiot" is to persecute and corner them into "enemy territory".

Also let's take a step back and differentiate between something being of interest to exclusively US enemies, that would be a detriment to the US directly, or a matter of international policy, which is the case of the Ukraine position you cited. The Ukraine position is not a threat to the US either way, it's just a position in foreign policy.

Edit: It seems the case of an example of that exact alternative to wikileaks cited did exist already, by micheal moore of all people, focused on trump however. https://www.huffpost.com/entry/why-im-launching-trumpileaks-...