[Wohlf]

I would assume it's because of intent. Companies want to give you credit, they just use your credit report to determine the likelihood of your future creditworthiness. They've determined that after 7 years your previous actions aren't indicative of future behavior.

Background checks on the other hand are serving their intended purpose, telling you exactly what someone's background is.

[Kelbit]

I think the intent of a background check in the context of employment is also to predict future behavior. An employer really shouldn't care that an applicant was busted for drug possession in college fifteen years ago - there's little change of reoffending, and the crime isn't super relevant to the performance of most jobs. On the other hand, if an applicant for a position at a hedge fund has a conviction for securities fraud three years' prior, you would not want to hire that person.

I think there's an argument in favor of requiring criminal background checks for employment to be run through bureaus that have a legal requirement to drop certain offenses off the report after a certain amount of time. The offender has repaid their debt to society through the punishment meted out by the court, there is no point in making them unemployable for the rest of their lives.