A) The entire county revolted at the same time, depriving the government of all political support.
B) The Kyrgyz security services were incompetent when they were trying to suppress the protesters.
C) Both A and B
From what I am hearing in the news, it sounds like C is the most accurate description of what happened. If the former government had a better security establishment, the protesters never would have gotten as far as they did, and the more successful the protesters were in pushing back the police the more support they received. Anyway, now that Kyrgyzstan has a new government (kind of... Bakiyev has issued a statement saying that he has not yielded to the opposition, so I guess he still has some support in the southern part of the country) it will have to reestablish the rule of law, which will mean quickly reconstituting the army and police so they can deal with all the looters. That shouldn't be too difficult since the army (or at least a sizable portion of it) now supports the opposition.