Candidates have to be realistic: most employers can't thoroughly evaluate every candidate, so certain red flags are going to be used as filters. Have a bunch of red flags? For better or worse, a recruiter or prospective employer is going to assume that where there's smoke, there's fire, probably without even talking to you.

At the end of the day, if you're looking for a job, it's up to you to sell yourself effectively. Far too many people assume that because they're competent, their competence will be evident to others. But hiring managers or recruiters generally don't see more than what you put in front of them.

If you're not strategic about how you position yourself and/or you're too lazy to put together a convincing "pitch", prospective employers will have no way of seeing the real you. And even if the supply of obviously good technical candidates is often limited today, the risks of a bad hire are generally too high to warrant taking a chance on someone who was incapable of presenting a compelling CV or "story" in the first place.