Because it is a completely unrealistic theory. It is just basic common sense. Just sit back and think about it. I mean really think about it.
20-50 individuals (depends on who you choose to believe) are murdered because they have dirt on an ex Potus and his wife who is an ex SOS. For this to be truth, you would need at least one (but more likely many) individual/s who is capable of killing that many people. The killers would have to be very adept at making the murders look like a suicide, without leaving evidence to the contrary. For the ones that are clearly not suicide, the killers would have to be adept at not leaving evidence that leads to their suspicion/capture. In this day and age of security cameras everywhere, DNA technology, etc, Cell phone pings, etc, it would be impossible to get away with that many murders without ever being caught/raising any suspicions. It would also be unlikely that no one would know enough about the murders/murderers that he/she would sell information to someone in the GOP (or to TMZ, etc), or go to the authorities.
It is really easy to apply logic, common sense, and critical thinking to the CDS, in order to believe that the CDS is a total BS conspiracy theory. Movies like Mission Impossible and The Bourne Identity are really entertaining, but they are not realistic representations of what is happening in the world.
