I think this debate was settled in the 80s when the Soviet Union fell over (and please no one tell me China, one of the most capitalist countries in the world, is Communist). Socialism is great in theory but has not ever delivered for the people. The amazing world we have today was built on two key things: science and capitalism.
I'm not sure if the collapse of the Soviet Union answers any of this - I mean, to what extent was it actually socialist, aside from in name? Sure, it had a few socialist traits, but wouldn't state capitalism better describe it?