Probably - in one way it is true (see for example Robert Brenner "Agrarian Class Structure and Economic Development in Pre Industrial Europe" _Past and Present_ 97, 1982.), but some argue (Blaut & Co, inter alia) that the plunder of the Third World was the decisive factor which implies that the ability to plunder was something unique and separate from the agrarian relations. I do not think that the latter argument has much weight in terms of explaining the main impetus of capitalist development - yeah, there was plunder, but to cross the pond and heist the boatloads of gold you need to be already fairly advanced technologically and organizationally, no? But it raises an interesting question whether capitalism was a "natural" outgrowth of the feudal agrarian relations - a stagiest approach to history may suggest - or there was some unique value added that sparked its development.
^^^^ CB: I'd argue that both alienating peasants from their land in England and foreign slavery/colonialism constituted the primitive accumulation of capitalism, as Marx does in _Capital_I in the last Section on the socalled primitive accumulation.
I was commenting on your idea that feudalism produced the working class, and capitalism didn't, but only produced a "yuppie" class. It gets to be a sort of metaphysical distinction, but if you say feudalism "produced" the working class, it would seem to be that feudalism produced the bourgeoisie too. A revolution in feudalism resulted in new relations of production: wage-labor/capital.