Of all the colonial powers, the Belgians in the Congo Free State certainly behaved the worst. Having known a few Belgians, it's hard to understand. They don't really seem like the kind of people who could have done the things that were done in the Congo, in the name of profit.
On the other hand, I could never bring myself to do the things Firestone employees did on their rubber plantations in Liberia, nor can I picture my family or friends behaving in this way, to make themselves rich. Yet I can't deny that my countrymen did terrible things there.
For this reason, it's hard to say whether the Congolese would have done much better under another colonial administration. They aren't even doing very well as a sovereign country. Some of the blame can be placed on the colonialists, who did a poor job of preparing the Congolese for independence, and drew national borders arbitrarily, without regard for the ethnicities and languages of the Congolese themselves.
Let's make up a new country, they said in their arrogance, we'll call it Hopscotch or Jump-a-Stump or whatever, we can name it after a mountain range, or a river, or a European explorer, and the people who live there, who thought they owned the land on which they lived, will just have to get used to the fact that they're now citizens of our newly created country. And if we have to, we'll use force to make it stick!
An attempt by the Congolese province of Katanga to break away and form a national identity of its own was ruthlessly put down, with UN assistance: how dare these upstarts presume to claim the right to nationhood, to redraw the existing borders, and decide for themselves what constitues a "real" country. Even today, some believe that today's borders and countries are inviolable, and must be preserved in perpetuity, even though common sense tells us that few if any contemporary nation states will appear on a world map a thousand years from now. It's all about man's ego, and his desire to be able to tell others what to do.
I've always thought the Congo was too large, and too diverse, to ever have been made a single country. It should have been broken up into several smaller, more easily maneagable ethnically-based states. Who really wants to be governed by strangers eight hundred miles away, in a city you've never seen, who speak a strange language, follow different customs, and know nothing about you or what your people need?