I have watched this evolve for ~12 years now. As thanatos519 sums up, when power is angered.....
At this time, any correctional aspect to this pursuit is long gone. The US Government is just letting it's anger rage unchecked - to no good or valid end.
It reflects badly on the US Government, it refreshes the ire of most Americans at the whole thing. They are angry the US Government committed their own crimes, they are angry at these unattractive truths being aired, they see that Assange also acted badly - but a large portion feel he was justified - most feel Sweden also acted badly by their lying accusations(assuredly instigated by the US). After 12 years it is time for the rage to end. The US Government should mend it's ways - if they have to do criminal acts to block the criminal acts of foreign governments against US interests (as I am sure there were) they need some judicial oversight to limit action against innocents of any country. That said, if they get evidence of foreign crimes against US citizens/interests the oversight should grant the powers they need. This data should be held in an encrypted form that can not be cracked - electronic 1 time pad - if there is such a method, and in an isolated computational enclave with no external connections so it can not be breached, and if by chance breached - it can not be decoded.
The UK courts approval of the appeal gives a chance for smarter people to come to the fore.
As you can see, I want the ability to safeguard the USA/citizens against the many very hostile foreign interests they face - but at this time, the offence is so remote from the punishment that all this farce reveals us the basic US venality - justice is long gone.