Because that checkbox undermines the security of EAC. Essentially it allows the service to run in the user space mode instead of kernel mode. This opens up a lot of hacking to games. It's absolutely not a solution epic wants to take with their largest game.

There is also a very good reason that vac is looked at as the worse anti cheat solution in the industry. So much so that CSGO has to have third party anti cheat in their leagues.