The has to be someone around to manage the crises! Therefore, I think crises management is a legitimate use of funds for corporations. Not everyone is able to handle a crisis well, and in some cases bringing in the pros is the way to go. Where crises aren't happening all the time, it usually makes more sense to outsource that job than have a department deticated to it.
Yes, crisis management firms are a legitimate use of funds for corporations, because it is a good thing that corporations want to help their employees with crisis management. There is something to be said for corporations that want to have the human resources available to help with crisis management. It is a personnel wellness provision.
These days, when corporations have just as much money and just as many employees as some of the more powerful nations on the planet, crisis management is an important aspect of the way they operate. There could be certain unthought of events that befall a company, and to protect its workers there needs to be crisis management plans in place.
I do not believe crisis management firms are a legitimate use of funds for corporations. The need for these services is a clear indication of a problem within the corporation. If the people can't solve these problems on their own then the corporation should fail or find new leadership, not invest money in another firm to help them fix the problems or hide them.