Flaws that would make someone unemployable?
-The most obvious thing that comes to mind is a criminal record. If you have one of these babies it's probably the kiss of death and reason why you find it impossible to get a job. Online applications are now screening out these people and as well companies are usually performing background checks. There are ways in some circumstances to get these erased, so maybe that should be looked into.
-Habitual bad interviewee and/or resume writer. No matter how many times you interview or write your resume, you are just employable because of the things you write or say (could be illegal things, personality problem, or just plain don't know what it means to be skilled at these). This problem is probably solved by going to a career centre and having your resume / interview skills looked at.
-Overqualified. I've heard numerous complaints about people with higher degrees such as M.Sc or Ph.Ds who can't find a job, because the hiring manager is intimidated by their credentials and fears for their job. Even a bachelors in engineering can be a death sentence. It's not uncommon for companies to receive hundreds, or sometimes even thousands of resumes, and not have anyone read their resume or recognize their skills.
- Too much confidence and/or in too good of shape. Interviewers are often intimated by people who are more charasmatic or confident than them and fear that they won't be able to control the employee or feel emascuated.
-Full heads of hair. This ties into my last point. The fat, bald and socially awkward interviewers are often intimidated by people who are in good shape and have full heads of hair.
With HR taking over and destroying companies these days, resumes are often filtered for the right buzz words and 'soft skills' rather than the technical abilities. Employers are often intimidated by people with more education and intelligence than them, and they are also intimidated by people with confidence who are in good shape and have full heads of hair. With the collapse of Nortel, the market is now flooded far past the saturation point and the likelihood of you winning the HR selection lottery recruitment process is almost nothing.