Even if one blamed Maya for her beyhadhness and the extremes she went to in making sure she always had Arjun, it doesn't necessarily mean she was born evil. Through all the torture and neglect she went through at the hands of her own parents, the ones whom ppl rely the most upon for love and support, she saw only a world of evil all around her (further reinforced in her exploitation by Rajeev). Growing up in an evil environment would have surely turned her into an evil person.
So I think it's important to consider the faults of those that created such an environment for her - Jhanvi, Ashwin and Rajeev.
Had she not had such a horrible upbringing, she wouldn't be looking for the innocence and simplicity which made her fall in love with Arjun, she wouldn't be so desperate for love, and she probably wouldn't have the quality which makes her Maya - her possessiveness and obsession with Arjun and her beyhadh fear of losing him.
So I think the wrong person happened to apply for the wrong job in the wrong company with the wrong boss at the wrong time - and when he did, Maya was unstoppable. Confused, vulnerable, lovable, innocent duffer + desperate, disturbed, manipulative, attractive, wealthy, intelligent woman = HELL
Although Maya's actions are unacceptable and definitely unforgivable, I don't think she is evil by nature, but because of the way she's been nurtured. So maybe blaming the ppl who nurtured her this way would be more justified, as they're the ones who created the monster in her in the first place.