Why the speaker of the poem "Locksley Hall" fail to marry his beloved?

Alfred Lord Tennyson’s poem is concerned with a man who returns to his childhood home and is overcome with nostalgia for his youth and his lost love. The young man had loved his cousin, Amy, and after loving him for a long time, she finally confessed her feelings. However, her parents opposed the match because of financial and social differences in their statuses. He rails against these “social wants” and “social lies,” and curses gold as something fools value.
In the present, back at the locations where they had spent time together, the speaker laments that she is his no more. Saying she is falser even than other women mentioned in songs, he says she was a “puppet” of her father and “servile” to a shrew, presumably her mother. We infer that they forced her to marry another man. This husband has a gross nature that will drag her down; the speaker even calls him “a clown.”
https://www.poetryfoundation.org/poems/45362/locksley-hall