For a female novelist, George Eliot sure didn't think too highly of female writers (or readers, for that matter). She even wrote an essay called "Silly Novels by Lady Novelists," and chose to write under a male pseudonym, rather than risk being classed as a typical "lady novelist." The typical female novelist, in Eliot's opinion, wrote "society novels" about well-to-do young women in the marriage market. These novels always end in the marriage of the heroine, who settles down happily to become a conventional wife and mother. Eliot knew this was bogus (see the "Marriage" theme), and so Middlemarch looks at the ways that this conventional "marriage plot" actually traps women (and men).
Unlike the women in novels with a traditional marriage plot, women in Middlemarch have personalities and ambitions independent of their husbands after their marriages; however, in order for the marriage to be successful, their personalities need to be suppressed to some extent.
Although women are, in many ways, more constrained by their social condition than are the men in Middlemarch, George Eliot shows that men actually suffer just as much from incompatible marriages as women.