Unable to setConsent to in when user was previously set to out on Alloy

According to https://docs.adobe.com/content/help/en/experience-platform/edge/consent/supporting-consent.html: "After a user has opted out, the SDK will not allow you to set the users consent to in ."

We would like to understand why this is? If a customer actively consents back in at any point in the future then surely we should be able to set the customer to consented on Web SDK?