I suppose that depends on the program. At my department Ph.D. candidates are researchers (it's the official title). Their job is not to learn how to produce ori

I suppose that depends on the program. At my department Ph.D. candidates are researchers (it's the official title). Their job is not to learn how to produce original research, it is to actually produce original research. Professors are not teachers, they are bosses who assign you to a project and make sure there's a budget to pay you. M.Sc. gives you the background to produce the research, but just like in the industry, you will learn while on the job. You could be doing equivalent work outside the academia with your M.Sc., in an R&D department of some large company. As for specialization, you must be extremely specialized to advance your field, which is a requirement for a Ph.D. The point is not to be hired because of your particular speciality, the point is to earn the highest "license to practice science".