Coalition governments are, for the most part, found within a parliamentary or some or of spin off a parliamentary system. The parliamentary system, by the ways it is designed, removes the population from the government more than a Democratic Republic, such as the United States. A parliamentary system takes away the ability for the people to choose who is in the nations highest spot, thus eliminated the possibility for as compelling of a compromise to be made as it allows and creates for both the ruling party and PM to be of the same party, thus allowing for less compromise and more one sided legislation, which is not in the interest of the citizenry and often conflicts with the vox populi (I have always wanted to say that word!). This lack of compromise removes the citizens from the process even more because it doesn't allow for (theoretically) citizens to change the balance of power, and prevent this stream lining of bill-passing.
However, coalition governments do allow for pre-floor discussion and compromise. This eliminates the ability for congress and the President of a Representative Democracy with a bi-party system, such as the United States, to become unable to pass necessary legislation. Also, coalition governments allow for constant change of power at the highest level, the president or prime minister, whenever decisions er the politics change. However, this also may be bad as it inhibits the PM from making correct that may be unpopular, due to fear of being replaced.
Basically, in conclusion, everything that is good about these two systems is also a problem. Government is about finding the balance between stream-lined decision making and the right of the people to choose and have a say in their own government.
