Once you've already made the decision that you will be retasking your military primarily as an instrument of domestic oppression on your own citizens for the foreseeable future (hence the need to re-designate all Trump supporters as "domestic terrorists") rather than as a defense against foreign threats (that you are already working for anyway) then political reliability becomes far more valuable to the junta in power than actual military competence. We see this pattern played out in every little tin-pot dictatorship around the world and throughout history. This way, even if by some miracle someone else manages to take office, the military will remain politically in the pocket of the other side until they can re-establish themselves in power again. We've already seen this happen when we found out that senior officers were "slow rolling". or even simply ignoring President Trump's orders (such as withdrawing from Afghanistan) until after the election. Eight years of Obama purges, and then the promotions of politically reliable leftist officers saw to that. The biggest fear of any dictatorship is a competent military. Too much chance that they might rise up against you. Best to keep it stocked with risk-averse incompetents who are all in competition with each other to see who can be the biggest political toady for brownie points.