Imaging tech is not the issue, we have plenty of ability to capture HD image (not movie level... but definitely internet level). Bandwidth, however, is a severe limitation.
Typically the technology aboard any space craft is 5 years older or older when it's being sent because it needs to be hardened and tested against the harsh radiation of space. So we're talking imaging tech from at best 2001 on this thing.
So yes bandwidth is an issue but so is the imaging technology. They couldn't put an HD camera on this thing.
Actually, I'm sure they could have, but a larger camera would have required a larger telescope in front, not to mention the bandwidth issue. Elsewhere in this discussion it's mentioned that the flyby data will be stored in two mirrored 8 GB units and slowly streamed back home through November 2016 (we'll get some lossily compressed images earlier, although nothing until the fly-by is finished and the main radio antenna again points at earth).
So an 8.2 inch mirror, largest ever sent to the outer solar system, with a 1024x1024 bits CCD, which isn't bad at all, weighing in at 19.4 pounds and an average power of 5.8 watts (http://pluto.jhuapl.edu/Mission/Spacecraft/Payload.php)
I'd like to point out that space is an extremely large and harsh environment. The three main issues:
1) Distances are huge. Light needs ~5 hours to travel from Pluto to Earth. This means high-gain (=large), directional antennas, and low data-rates to make sure you actually receive the same data that the craft transmits to you (and vice versa).
2) Electronics need to be shielded from radiation and cosmic rays. On Earth, the atmosphere does a this for us (and we still get hit by cosmic rays, leading to things like randomly flipped bits). If you have a space-craft that cannot be directly controlled from Earth (because, 5 hours one-way communication time), you need it to be somewhat autonomous. Random bit-flips can spell disaster, so you need to either bring a ton of shielding, redundant (and well-tested, aka "outdated") systems, or both.
3) All these things add mass to your vehicle. Mass is the single largest cost driver in launch operations.
In summary, space is difficult and expensive to get to and operate in. This costs money. Money is finite, especially in a world where many people would like to see space exploration funding cut because it provides no immediate tangible return.
"We choose to go to the moon! We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard..."
According to the Office of Management and Budget, NASA's 2014 budget was $17.65 billion. Total spending on the military of the United States in 2013 was $610.1 billion. That means that NASA received the equivalent of 2.8% of our "on the books" (e.g. no emergency allocations) military spending or 0.492% of the total Federal budget.
Meanwhile, NASA delivers pictures of planets (no apologies, Pluto is a planet) so far away we can only barely see them from Earth and has provided the technology to park multiple upon multiple communication devices in orbit and around our solar system.
I can only imagine what they'd do with over $600 billion each year.
The common thing I see in your comments is that you have seriously inflated, unreasonable expectations. No one promised HD streams from Mars. You can't have that, for the reasons outlined by other commenters. The problem isn't with NASA, it's with your expectations. We're not in XXIV century yet.
Outside of military technology? Clearly, you have not been following the the JSF (Joint Strike Fighter) program. Stealth, multi-purpose, VTOL fighter-jet, able to replace most combat aircraft for all three branches of service. Oops...
If you're actually interested in pictures produced by the current Mars rover, I can recommend the interactive New York Times website dedicated to its progress[1]
New Horizon left this Planet on Jan. 2006, you have to consider that, too. We have advanced imaging tech from 9 years ago aboard.