I agree with your theory. For a relationship or marriage to work, there must be compromise. The question is about what each of both couples are ready to compromise. I don't see any reason why couples should be using different blankets. In Nigeria today, I can say that many couples are growing apart because they are not ready to adjust on their individual preferences in order to meet at the middle. It may not be a sweeping statement. Some couples may have genuine reason for doing that.