Thing is that the west really doesnt know what they are likely to end up with in Libya. With all the tribal factions the dream of a western friendly democracy could end up in a perpetual civil warfare state like Iraq.
Trying to unify some countries under a democratic system is like trying to mix oil and water (no pun intended). Sometimes a ruthless dictator is the only way to pull them all together. Thats what happened in Iraq when the League of Nations threw together a bunch of different people and called it Iraq. Same, same in northern Malaysia when the Poms gave part of Malaysia to Thailand.