I think you're mixing two things:
* if a site owner receives a DMCA notice and believes the content is not infringing they can just do nothing and / or tell whoever sent it to get bent, sender may escalate to the courts
* service providers which want to be protected under safe harbour must "act expeditiously to remove purported infringing content" regardless of counter-notices, this is not an either/or situation
Content should be restored 10 to 14 days after the counter-notice is sent to the original claimant unless they engage in legal action, but it must be taken down either way:
> 17 U.S. Code § 512 (c)(1) In general.—A service provider shall not be liable for monetary relief, or, except as provided in subsection (j), for injunctive or other equitable relief, for infringement of copyright by reason of the storage at the direction of a user of material that resides on a system or network controlled or operated by or for the service provider, if the service provider—
> […]
> 17 U.S. Code § 512 (c)(1)(C) upon notification of claimed infringement as described in paragraph (3), responds expeditiously to remove, or disable access to, the material that is claimed to be infringing or to be the subject of infringing activity.
> […]
> 17 U.S. Code § 512 (g)(2)(B) upon receipt of a counter notification described in paragraph (3), promptly provides the person who provided the notification under subsection (c)(1)(C) with a copy of the counter notification, and informs that person that it will replace the removed material or cease disabling access to it in 10 business days; and
> 17 U.S. Code § 512 (g)(2)(C) replaces the removed material and ceases disabling access to it not less than 10, nor more than 14, business days following receipt of the counter notice, unless its designated agent first receives notice from the person who submitted the notification under subsection (c)(1)(C) that such person has filed an action seeking a court order to restrain the subscriber from engaging in infringing activity relating to the material on the service provider’s system or network.