the reason why so many people rely on hitler analogies is because in these relativistic times adoph hitler is one of the only historical figures who is almost universally accepted as bad.
if you use, for example, a franz ferdinand comparison you not only run the risk that someone will think you're talking about a band, but also have to contend with the fact that a lot of people don't know who the archduke was and that there's no near-universal consensus about whether he (or gavrilo princip) was a good guy or bad guy. "hitler" has become a shorthand for not just evil, but unquestionable evil. if you want to brand something as evil without having to bother with a real analysis of the relative positive and negative features of a historical figure, hitler is the only obvious choice.
in just about every case, i think the use of a hitler analogy is both wrong and a sign of weakness in the hitler-analogizer's argument. (which is why n-pod's inability to marshal any other argument is so revealing but it's also inevitable that the comparison will remain popular.
