I do feel bad for the Duke but Chloe doesn't really think the Duke cares for her in that sense because he has been through a lot. He wasn't able to properly express his emotions and was forcefully given love by other ladies who only sought after his wealth, title and looks. So Chloe clearly assumes that she should not express any sort of love and simply be kind to him so he doesn't feel uncomfortable. I don't really see how the drama in this manhwa is "forced" but I can understand that Chloe may seem a bit difficult at times. But she's only thinking that the Duke doesn't deserve to feel like someone is forcing their love on him. So honestly you can't bash Chloe for saying "I won't love you" because the contract they signed also made sure that there would be no love in their marriage just as the Duke had wanted. He has to confess to Chloe himself and ask her to change the contract with him or else she really can't start to see him in that way because the contract and the way the Duke has lived prevents her from doing so.