There is plenty of opportunity for good management consultants - key word "good." If you know your stuff and have an impressive track record, that's all a business owner wants to know. Keep making people money, and you will always be working. Keep making yourself money, and you may be able to quit working sooner than any of your friends.
If you can establish yourself within the industry and have a history of being financially and strategically beneficial to your employer and to your clients, you should have a long, fruitful career as a management consultant. Now to work on your love life!