Jack of All Trades vs Master of One for Designers

Every year, large batches of design students graduate and launch their careers in the market. Some of them land in proper places, which groom them professionally and set a solid career path for a successful future. Then there are designers who are not so lucky, who do not find the kind of professional approach they were looking for.
To help these designers cope with their career decisions, there has been much literal support through books, websites, and blogs, and even debates on issues like whe