It's like going to lunch with a group of people. If it's just you, you can go wherever you like. Once it's with your partner, you have to take their interested into account. Have you tried planning a lunch for 5 or more people, taking into account dietary restrictions, location, time, etc.. ? And imagine when it's 400 people - now you need to make sure the restaurant can hold that amount of people, and if it's available during times that you like. The more people that are involved, the more variables are introduced that influence decision making.