IANAAP, but I saw a similar question about how the Hubble space telescope could only get blurry pictures of Pluto. The answer was that it was akin to using a microscope as a telescope (or vice-versa), if that makes sense?
Not really. The problem isn't that Pluto is too close (Hubble has taken excellent pictures of Mars), it's that Pluto is tiny, specifically in angular size.