Part of it may be because some of Wikileaks high value contacts are now in places where they are vulnerable (which adds weight to the call to Pardon Snowden, it would make it much easier for WL to release dirt on Putin and company, assuming they have any).
Assange set himself up to be easily corralled, not the smartest thing but he's not the first (and won't be the last) person that makes it into the limelight and ends up tripping up because of it.
Releases themselves can be independently verified, what data that is there that ends up labeled factually accurate is a great gift and I'm very happy they did what they did, however we will need more or other organizations like WL if we're to get the whole picture.
That would help in another way, you could immediately check for any modifications or selective withholding of information from the various sources.
Are any of the releases discredited?