Some decisions that for the common good of the entire community might require some group of people to make some sacrifice e.g. farmers might have to leave their family land and go to some other place in order to make space available for some new industry. While this new industry can bring prosperity to the whole area and can offer better jobs and standard of living to the farmer's own children, many farmers would be reluctant to leave the land that has been ploughed by their forefathers, espacially if the land is fertile. Convincing them to accept monetary compensation or another piece of land can be a very difficult task in a democracy as compared to a dictatorship. Displacing millions of people for building a dam, as the the case when constructing the Three Gorges Dam in China, might have been much more cumbersome in a democracy.
Democratic system of governments generally have an extensive system of election of government. Dictatorships do not need to spend effort in developing and mainitaining such proceses and are hence free from this hassle. A comparison of recent elections in Zimbabwe with the current ongoing US presential campaign clearly shows the former to be much simpler than the latter.
Democratic systems by nature prefer to have a system of check and balance so that all power is not rested in one indivdual. This can sometimes lead to situations where doing any legislation becomes very complex or nearlly impossible. In a parilamentary form of government a hung parlaiment or in a presidential form of government a President and Parliament from different political parties are