I used to think that it was just a way to stop people complaining in meetings. To give them an action to sort out whatever they raised as an issue in a team meeting.
Well, it might be, but it is also a great gift for development. If someone cares enough about a subject to raise it as an issue amongst their boss and their peers, then it must be something important to them to change. Allowing them to take responsibility for sorting it out rather than just stepping in to provide an answer is a great way to get someone to grow. It shows that they can take responsibility for everything in their lives and therefore work to change it. It also serves a great purpose to teach them time management. They are not going to have anything taken off their plate, they must find time to do sort the new issue too. Giving someone something they are passionate about is the best way to prioritise and make things quicker as they will have to find a way to make the things they are less interested in, or less important, be done in a faster time to free up space for this new project. If they were not passionate about it and they were just complaining, then this a great lesson too. It is easier to criticise than it is to do. No one is going to sort out shit for you, you are going to need to do it on your own.
Not complaining is a great habit to get in to, although one that I find particularly difficult in our society as we are surrounded by it. All the news is complaining. About something someone has done, something someone has not done or something someone should have done better. There are not many influences around us that teach us to just make the change ourselves in whatever version we can influence. And then to build on it. This is how everything gets done but apparently is not important enough to be taught at school.