I'm pretty sure that would be an allowed reason to reject.
But what if you are a small business and don't want the person there because you don't want the reputation of having someone with that particular criminal past working for you? Say you are a construction company that specializes in large play areas. Technically a child should never be on site while building the play area, and your workers will be gone before it is open for kids to play on, but the mere reputation association being made could cost business.
Is merely the possibility of a bad reputation reason to reject? If so, the law is effectively pointless.