Lunch is the highlight of the workday for many, so it is important to put some effort into it now and then. When you are behind on several deadlines and your manager is getting on your nerves, it is nice to have the sweet embrace of tasty food to fall back on. It is fuel for wherever the afternoon is going to take you.
It is no wonder that some kind of lunchtime arrangement is a perk of the job with many companies. They know that their employees will be more compliant when they are not hangry. On top of that, a team eating lunch together is one of the simplest ways to facilitate workplace bonding. While it isn't everybody's favorite thing, it is often important for morale and productivity.
At the same time, as soon as lunch becomes a group enterprise, there is an element of project management brought into the mix. Everyone's opinion has to be taken on board, even if it is impractical or annoying. Some would argue that the person in charge of bringing the food has the ultimate say in the matter, but that isn't what everybody would like to believe.