Can a generic top-level domain (gTLD) just be considered as part of a web address or should it be considered a source of the domain name registry? Top-level domains (TLDs) are administered by the Internet Assigned Numbers Authority (IANA) for the domain name system we call the internet.
One can simply see it as a suffix at the end of a domain name (DN). The USPTO is concerned that the general public would construe the suffix as part of the DN and not serving as intended which is to be a source indicator for the registry. Given that concern, it does not meet the criteria as a valid component to be considered as inclusive in a trademark.