You have to speak in generalities if you have to convey your message to a very large audience. You need to make certain assumptions about the people you are speaking to and deliver the messages. Yes, there will be many if and buts but exception does not ruin the rule. Our decisions and policies must not be based on the exceptions but framed around majority of cases. Exceptions do not disprove the rule. If we try to address each and every different case, then we cannot implement anything and take any decision. You cannot take an action if you try to mitigate all the risks associated in reaching a goal. You need to first start and then improvise during the process.
Do read the Disclaimer