People hate Clinton for a number of reasons. Some of these reasons may be legitimate; some seem irrational to me; others may be simply differences in the natures of people who hold values opposite of Clinton:
’Black and White’ vs. 'Shades of gray’
As discussed above, Clinton epitomizes the tendency to see the world in shades of gray, vice black and white. As such, is it really surprising that people who don’t like him are of the opposite tendency, and thus refuse to acknowledge anything good about him? (E.g., when Rush Limbaugh was on Letterman, he asserted that there was nothing at all that impressed him about Clinton. A few minutes later, he lambasted Hilary as a poor example for feminists, since, rather than achieve success on her own, she had simple “latched on to a guy who was going places”. At which point, Letterman inquired, “How did she know he was going places if there was nothing impressive about him?”) 
Military Culture and Mindset
Many of Clinton’s most rabid haters either served in the military, or come from a culture that highly values it. Is it really surprising that military-oriented individuals would be more aggressive and less conciliatory in their opposition? Soldiers don’t win wars by compromising. And while the right-wing media certainly made hay with this, Clinton is not without blame – remember his letter to his ROTC commander, in which he said he “loath(ed) the military”? Phil Gramm and Dick Cheney took deferments during Vietnam, but they never said they loathed the military.
Adult rebellion (bear with me – this one is very half-baked)
Much was made of the fact that Clinton was our first baby-boomer President. Equally important is the fact that he was a baby boomer who went through a baby-boomer adolescence – he rejected ‘establishment’ values, protesting segregation and the war in Vietnam.
Like many Clinton supporters, I went through a similar phase – although segregation and Vietnam were moot issues by the time I was old enough to hold much of an original opinion (I was born in 1959), I went through a knee-jerk criticism of every authority figure in the world, followed by moderation after growing up and learning a little about the world. I might even assert that this is a normal phase of adolescence. Contrast this with someone like Dan Quayle, who was born around the same time as Clinton, but never really rebelled against the system.
Fast forward to 1993. Many life-long Republicans – people who had never really ‘questioned authority’ – now found someone they disagreed with in authority. But these people weren’t teenagers – they were grownups with families and mortgages. Is it really surprising that their views were much more entrenched than mine had been when I was in their shoes?
I speculate that this is one more reason why Clinton doesn’t have many moderate detractors – he has moderate supporters, who rate him slightly above average – I am one. But damn near everyone who doesn’t like him really doesn’t like him.
If you disagree with any of this, please do so in the most blistering, hyperbolic language you can – it will underscore my point.