This is a very interesting hypothetical question to consider, and I believe the answer can be found in Chapter Ten of this great novel, when Frankenstein comes face to face with his creature on top of a mountain. The creature justifies what he has become by refering to the way that he has been treated by both his maker and by other humans. His response seems to make it clear that even if Victor had managed to accept him and care for him as his maker, he still would have been greeted by scorn, hatred and anger by the rest of the world. Note what the creature says to Frankenstein:
Believe me, Frankenstein: I was benevolent; my soul glowed with love and humanity: but am I not alone, miserably alone? You, my creator, abhor me; what hope can I gather from your fellow-creatures, who owe me nothing? They spurn and hate me. The desert mountains and dreary glaciers are my refuge... These bleak skies I hail, for they are kinder to me than your fellow-beings. If the multitude of mankind knew of my existence, they would do as you do, and arm themselves for my destruction. Shall I not then hate them who abhor me?
This passage is key as it presents the idea that the creature was made to be benevolent. What has turned him evil is the way that he has been treated by Frankenstein and by other humans. We can almost understand his logic as he justifies his evil nature. Thus, even if Frankenstein had greeted the creature with love and nurtured him, he still would have been abhorrent to other humans, questioning your hypothesis. Frankenstein's love and care would have greatly helped the creature, but the sheer level of hatred and anger the creature would have incited might have had the same effect in the long term.