The reason bureaucracy is so big is the fact that there are so many jobs in the government and so many projects to complete and so many problems to take care of that groups of people must work on them each. This sounds great that all these people are doing these jobs for government and completing them. If al the work that was done by these different groups was left in the hands of one person, none of it would get done. This is one of the ways that bureaucracy helps government.
On the same point, with all these people in a bureaucracy slow work down. Say you had a project to complete and there is ten people working together. Each person wants to have his or her own say on what goes into the project. Now if each of these 10 people were representing another 10 people who were working on the project, it can just cause more problems and make it difficult to get anything finished. The project would take much longer to finish.
In a large bureaucracy many views and ideas are represented. This could be a bad thing, as mentioned above, and a good thing. When so many ideas are represented there are more options on what should be done. Also if a little of all the views and ideas are put into a final solution everyone is happier.
Although a large bureaucracy can hurt government, by being slow and had an immense amount of views and ideas, but it also help, in distributing work amongst people and having different views and ideas.