You raise some interesting points, but I think you have miscontrued Engels' thesis--which is admittedly a short quote from a much longer selection of essays related to "historical materialism." Engels like Marx rejects traditional philosophy--instead of metaphysics or ethics, human life is first and foremost economic: production, means of production, and exchange--the ways of distributing and controlling, and exploiting the commodities produced by labor.
Thus cultural products such as literature may also be interpreted as products of class antagonisms or reifications of bourgerois economic values.
Could marxist ideas be retrofitted
and adapted to cyberland?