If they wanted Ragini and Lakshya to come about, they could've done so easily without making Ragini evil.
Now, on national TV, they're showing black magic being used (successfully!) to marry a boy. That's not the sort of message that's supposed to be sent out to audiences. And if Ragini does turn good, then even worse. You adopt the wrong methods and you think nothing wrong about it.
It's just annoying how Ragini is shown to have no heart left while even Sanskaar has reformed.