What an excellent question! Mary Shelley created her novel as a response to a contest...several well-known contemporary writers were together and forced inside due to poor weather, and they "dared" one another to create a ghost story. Frankenstein was the result of that dare, as much as the result of all the conversations Mary Shelley had been present to hear regarding the scientific advancements of the age, Darwin's experiments on the Galapagos Islands, survival of the fittest, and man's moral responsibilities. It was also a result of her own abandonment issues and how she learned about her own dear mother who died shortly after Mary was born. Mary Shelley learned about her mother through reading her mother's writings.
Because of this, and knowing her definition of unconditional love as Caroline Beaufort and Elizabeth lived and shared it, Mary Shelley did not create a "hideous progeny" but a lesson for all of us to learn. Even today people abandon their children or abort them rather than take responsiblity for their actions. Mary Shelley is sharing with us the lesson we should all take seriously to heart: think before you create. Be ready to love and care for your child regardless of the consequences.
While it is called a "hideous progeny," I think that Shelley has a different approach to her novel than Victor to his creation. I don't see her as abandoning it with the zeal and intensity that Victor did to his creation. When confronted with the physical horror and psychological terror of his creation, Victor flees, seeking to forget. I feel that Mary Shelley understood the power of the work. She grasped that it was an indictment of both Romanticism, her husband's belief system, and the Enlightenment era, her father's belief system. It might in this domain that the work was seen as a "hideous progeny," in that it rejected both dominant intellectual currents of the time. Yet, I think that Shelley understood this and did not shrink from it as Victor recoiled from his own responsibilities and duties.