Enough with this idea that humans only do good things for profit.

You're totally right! Marx says that material conditions determine human nature. Living in an atavistic capitalistic society teaches us to be greedy cretins. It doesn't have to be like that!

"It has been objected that upon the abolition of private property, all work will cease, and universal laziness will overtake us.
According to this, bourgeois society ought long ago to have gone to the dogs through sheer idleness; for those of its members who work, acquire nothing, and those who acquire anything do not work. The whole of this objection is but another expression of the tautology: that there can no longer be any wage-labour when there is no longer any capital." Marx & Engels, "Proletarians and Communists," The Communist Manifesto, 1848