I think this "access" meme is over-used and unconvincing. In any case it really applies only to some true pedophiles (attracted to prepubescent kids). That priests are overwhelmingly gay and that their attraction to teenage boys (to whom indeed they had privileged access) is of a piece with their gayness rather than with pedophilia or even ephebophilia seems pretty obvious to me. Especially in the case of behavior reaching back to the 1970s,  I think that gays were not very worried about age barriers back then, and even if they were, legal discrimination against gays as such may have led many to say "might as well be hung for a lamb as for a sheep!" Now memories have been sanitized, with the help of political correctness.