There are plenty of great reasons to get a large group of people together either for business or pleasure purposes. The big problem with having that many people in one place. The average person does not have private accommodations necessary for a big get-together and those who do may not have an appropriate setting.
Family parties, even big ones such as weddings, anniversaries, and reunions are often great in an informal setting. There are times, however, that even those are better in a more formal setting. In some instances, a casual setting is completely inappropriate. Conferences and other business functions require a pristine, professional setting. Clients and associates should experience a business environment for those sorts of functions.
Fortunately, for big events here are options available for all occasions. A simple search of function rooms for hire will help locate the best option.