For most people it is an emotional trigger which they don't understand themselves. So any real answer as to why will actually be wrong for the majority of people enforcing that rule. The answer that is true for the majority is that it is the party line. The reasons they would give obviously don't stand up to scrutiny because they are mostly logical fallacies which were used to brainwash them. The problem with those people is you can't simply expose that their reasons are fallacies and make any progress because when their programming is challenged there are several fail safes built in that cause them to get defensive and violent.

So there is nothing that can be said that is true for the majority of people participating that will make any logical sense because their reasons are not logical. As for why they have been brainwashed in that way by the elite we can only speculate.

To get at that you have to look at the totality of mainstream propaganda. It seems that the intention is to make the public as confused as possible because that makes them the least dangerous to the establishment and the most controllable. So everything is systematically inverted. Women are stronger than men. Blacks are smarter than whites. Jews are oppressed. 2+2+=5. Nationalism is racist. Men can have babies. And on and on.

There is a famous quote from a former CIA spook that goes something like this: when everything the people believe is wrong then our job is complete.