It is very easy to see why.
It is quick, inexpensive in comparison to high court and litigation costs, its informal nature allows the parties to focus on resolving the dispute rather than prosecuting it, and perhaps most importantly of all it has a very high success rate.
By focusing on resolving the issues rather than focusing on the cause of the dispute the mediator is ideally placed to help the parties resolve the problem. The process is entirely confidential and anything said by either party to the mediator cannot be repeated to the other apart from with express permission. So those involved in the dispute have the confidence to say exactly what they feel without worrying that they might give the other party in the dispute any form of advantage.
Mediation is a resolution system that allows the parties in the dispute to reach their solution, to their problem and to conclude matters to the satisfaction of all. Unfortunately this is rarely so with more traditional routes such as court litigation where inevitably even the victor does not get quite what they wanted, and often the final ruling will not be to the satisfaction of either party involved. By choosing mediation as a dispute resolution you choose the opportunity to bring your case to a quick and satisfactory conclusion.
And for those occasions where whatever reason resolution cannot be achieved, due to the entirely confidential nature of the process neither party would gain any form of advantage in relation to matters if they have to continue