This does not sound right to me. It would be correct if all companies and their hiring managers had the same requirements/looking for candidates with the same qualifications - but they're not.

Obviously as a hiring manager you're looking for a hard working individual with a number of successfully completed projects and glowing referrals from multiple places of employment, but you're also looking for a person with expertise in particular technologies/industries/whatever other areas of expertise. To a large extent requirements for each role are unique, however many do have some overlap.

So being rejected from one position might simply mean there's a misalignment between what the company is looking for and what the individual has. Which might not be the case with other companies.

So if we're seeing increasing number of candidates being consistently rejected at multiple places the question "why" is a valid one.