You can't subset a fair use argument like that and necessarily get a valid defense out of it. Fair use is essentially arguing "I infringed copyright in one of t

You can't subset a fair use argument like that and necessarily get a valid defense out of it. Fair use is essentially arguing "I infringed copyright in one of the narrow ways expressly allowed for the public interest". If you remove the public interest, you probably fail the first pillar. If you were doing something else (e.g. acting as a public archive), you might not need a fair use defense because you'd fall under different rules.