Theory: After his resounding success in various ventures Musk was offered entry into the global elite. He only would have had to do something horrible on camera such as murder a child. With the blackmail secured the group would have felt confident enough in its ability to control him to make use of his companies and ideas.
He refused but was too smart to publicize the offer. (which was made way too carefully for him to have evidence of even if he wouldn't have died in a tragic accident) As a result billions have been poured into shorting his company and trying to get him prosecuted for this or that. The notorious They don't want someone with his wealth and possible future power whom they can't control.