Frankenstein certainly does nothing to prevent the monster from doing evil. As the monster’s creator he has a certain responsibility towards it which he does not honour. On the contrary, he endeavours to shun his creation completely, leaving him to struggle alone in the world without guidance.
The text makes it clear that the monster is not inherently evil, nor inherently good. The story plays on the idea popularised by the famous eighteenth-century philosopher John Locke that human beings are born as a tabula rasa, a clean slate, and how they develop is due to the nurturing (or lack of it) that they receive; we see this happen with the monster.
If anything, the monster shows a disposition to good to begin with; he is in a state of pure innocence, and wonder at the world, but he receives no help; everyone he meets is appalled by his unnatural appearance. The monster makes it clear to Frankenstein that his unhappy isolation is the cause of his sinning.
I was benevolent and good; misery made me a fiend. Make me happy, and I shall again be virtuous. (Chapter 10).
Frankenstein can be excused for being revolted by the monster's appearance, and he is overcome with horror as he realises the absolute enormity of what he has done, but he could have done more to understand and help the monster, especially after realising that he has become intelligent and articulate. instead, he continues to repulse him, only half-heartedly beginning upon a companion for him at his request, and then wholly reneging on that promise also. It is no surprise that the monster should feel wronged by his creator. The epigraph to the book, taken from Paradise Lost, John Milton’s epic account of man’s creation and subsequent fall, is applicable to the monster’s situation:
Did I request thee, Maker, from my clay,
To mould me man ? Did I solicit thee
From darkness to promote me?
The monster compares himself both to the fallen Adam in his despair, and, even more, to Satan, the fallen angel, who turned to evil because of envy and misery.
Frankenstein does not make the monster evil but neither does he do anything to help his development. He ‘wantonly bestow(s)’ life on him (chapter 16) then abandons him. Frankenstein is in no small part to blame for the monster becoming vicious.