Because our software is not web application or http scanner. Our software scans hosts. Hosts are either specified by a domain name or IP address.
A URL consists of more parts beside a host. When your browser connects to a HTTP server it uses the host in the URL to resolve the IP address of the HTTP server. The browser sends a HTTP request to the server including the full URL. The HTTP server then decides which content to return depending on the URL of in the request (and additional parameters of the request). Different URLs can also point to the same host.
Thus a web application scanner acts on a different layer (HTTP) then our software (mostly Internet Protocol). Our software scans hosts (some device with an IP address) for possible vulnerabilities and not HTTP URLs.