The second is what you correctly note- the increasing use of morality for all arguments. When you certain arguments or viewpoints are believed to be not just incorrect, but to be immoral, then it becomes easy to attack the individuals making those arguments as immoral. If, for example, you think that people who enjoy pineapple pizza are not just terrible bard-lovers, but also immoral bigots, then you will likely find it easier to behave cruelly to them (and those people, in turn, will behave cruelly to you).