I believe a propensity to blame others for one's own failures or not is not a national characteristic but a personal characteristic. How do Belgians feel about a person blaming others for his own failures?
I happen to think that countries (and companies also btw) are not all identical. They feature a thing called culture. This culture is shaped over centuries by various aspects including the natural environment, religion, past leaders (political, artistic, sports,...),...
There are certainly important personal differences also and one is only influenced by his cultural environment.
So to answer your question I do believe that there is, unfortunately, in Belgium an overall tendency to be jalous of the success of others and to blame lack of luck for one’s failures. Not everyone falls for it obviously.
And I believe, from thousands of touch points, that taking responsibility is part of the American cultural tool kit. Again especially among people describing themselves as Republicans, which as we know clearly has nothing to do with Trumpism.
Cheers,
Bernard