Romance and marriage are atypical subjects of speculative fiction, usually either consigned to the B-plot or give short-shrift if included at all. That’s fine: not every book must contain every possible element. Absence of a wooing, dalliance, or long-term relationship should not be grounds for legitimate criticism of a work.
Tolkien wrote a romance without a great deal of romance. What romance did reach the page was chaste, the courtly romance of the troubadours. This is perhaps better exemplified by Gimli’s love for Galadriel than the decades long trials and courtship of Aragorn and Arwen. That is the story the Good Professor was writing and it worked.