Initial conditions, I mean true initial conditions, before Europeans arrived, were equally bad. Instead of Europeans, it were African kings, chiefs and warlords who terrorized the local population. Europeans hardly destroyed anything, because there wasn't anything to destroy. After 1908, they've started to develop the country and they'd perhaps succeeded, if they had enough time. Another 100 years or so.
The kicker, for Africans and everyone else, is that the actual conditions before European interference are pretty murky.
So, those who wish are free to imagine highly improbable utopias of bliss and goodwill towards all men, and those who wish can indulge in equally improbable visions of dysfunctional African gruel-fests since time immemorial, since how things really worked is left mostly up to conjecture. This is otherwise known as the "postcolonial situation".
The bits of consistent history we seem to be able to access to say that European interference consistently altered the ballgame for Africans:
Slave trading, one of these things people will say "OMFG the Africans did it to themselves" over, which skirts the fact that the circuit and scope of the acitivities were radically altered by integrating Africa in a European global system of trade. It's simple supply and demand, more demand from the new European designed world economy, greater potential profits, adds up to an increase in scale definately capable of severly disrupting west African societies for a very long time. Add the introduction of European fire-arms to build the African varieties of "Gunpowder Empires" (buy guns, attack your neighbours, take slaves, buy more guns, rinse and repeat) also fuelled the process.
The slave trade brought down large obviously functional African polities like the kingdom of Angola, despite the Angolans adopting Christianity in an attempt to avert this disaster made in Europe.
A more recent examples of a functional African polity was located precisely in the contested border area between southern Sudan and the two Congos. Who ran the show there in the 19th c., prior to the advent of the Europans? Why the princes of the house of Avongara, uniting a considerable number of millions of Africans in the Azande Federation, size three times France.
They were hardly peaceful towards their neighbours, but they are one of the anthropologists' favourite polities, specifically because they were masters of the integration of conquered peoples. They were wonderful at keeping internal peace, and they were one of very few African polities capable of completely interdicting slave hunting in their area creating a "Pax Zandica".
Their fate? Broken up between the UK (Sudan), France (French Congo) and Belgium (Belgian Congo) in the first decade of the 20th c., with conscious relocation of the entire population to break patterns of dependancy on local princely power in favour of dependancy on colonial officials.
In order to avoid southern Sudan and north east Congo turning out like they now have, the Europeans could have left the Azande to run the show. No way of knowing how that would have turned out, put the fingerprints of European colonialism would at least have been less visible.
Otoh, Winner is perfectly right in that the Belgium Congo colony was at least no worse than other European colonies in Africa, and better than some. On the normal charges of paternalism and infrastructure designed to haul the loot out of Africa asap rather than actually benefit the natives, it was of course equally guilty along with the rest of the bunch.