The translation from Republic is a little more nuanced – Plato was obsessed with order and assumed everyone was just as obsessed as him, and carried that assumption through to a desire to hold office.
So Plato assumed everyone went into office for the same reason. The whole passage the paraphrased quote comes from goes something like this:
“For they are not desirous of honours. It is indeed necessary to add some compulsion and penalty on them if they are intending to be willing to rule. This is likely the reason that a willingness to go to office without facing compulsion is considered shameful. But the greatest penalty is to be ruled by someone worse if a person is not willing to hold office himself. It seems to me that people of propriety hold office (when they do) because they fear that outcome and that they enter into power not because they are going after something good or because they enjoy it, but because it is necessary and they are not able to entrust it to those better than themselves or their equals.”
Which, obviously, is not true. Some people just like power. Those same people enjoy sowing seeds of discord that they never have to actually solve, in order to keep it. They are able to do that, because many of us in the media work to make their offerings seem sane and normal.
