@Jorgelino Hitler is not a very good comparison. It's hard to have a reasonable discussion surrounding Hitler because of the extremes of his crimes and the extreme feelings about them and that whole regime. Furthermore, I just don't think it fits. Hitler (or dictators in general) force their will on others, usually at the point of a gun, with no benefit offered to the ones oppressed.
In the Kaiji series, people are given choices, and there is potential for them to see great benefit from their gambles. The competitions are often fair (though in a couple instances weren't). You may say that the characters faced economic pressures or other similar indirect psychological pressure to make a choice, but that is far away from having an actual gun at your head.
If a dictator wants something, they will make it happen. Kazuya deserves some credit (though we can debate how much) for the element of fairness in competition he maintains.