A profession's a well-defined body of knowledge which is learned intellectually, and with an organizational sense. To enter a profession, a person has to undergo the relevant course and write the exam. It's primarily concerned with serving others. Pros work either for charges or fees.
Requirements
A profession's an occupation which requires special skills. It's backed by knowledge and training. It needs skills and a special body of knowledge, formal training and experience methods, a company, ethical codes of conduct and money.
Reasons why it's not considered a profession
Management's a well-defined body of knowledge. There are organizations made to regulate whatever managers do. There's also a code of conduct for managers. But management's not considered a profession because it needs a minimum number of qualifications, it's essential for its' practitioners to register themselves with a professional body (though that's not obligatory) and there's no universally accepted code of conduct.
Reasons why it's considered a profession
It's considered a profession because it consists of special knowledge, has formal training methods, fees, has a code of conduct, and has a representative organization
Conclusion
Management's a new branch of knowledge. It's developed as a profession because of the need for acquiring skills to solve problems. Thus, it's not a full-fledged profession.