Chris is saying that, for him, 'socialism... is not about hippy-dippy all-you-need-is love idealism'. I agree - because love isn't all you need and, anyway, universal love isn't a sensible expectation. I argued for this view at length in the series I recently posted about Jerry Cohen and the camping trip. Here, I want to set out, briefly, argument for the proposition that utopian ideas about human nature aren't just unnecessary for socialism, they're inimical to it.
(a) As conceived by socialists, socialism will be a desirable state of affairs, in which the most basic oppressions known to humankind have been eliminated so far as possible or else curbed, alleviated.
(b) Socialism in this sense therefore requires (at least) the rule of law, pluralist democracy and elementary protections of basic human rights. (Actually existing socialism, as it was once called, failed on all these requirements, but I'm assuming that socialists today aren't aiming for a socialism of that kind but for a better one. Socialists falling outside this assumption ought to be opposed by anyone of liberal and democratic outlook.)
(c) Supposing either that human beings are completely benign or that they can be made so by changing human nature to remove everything bad from it weakens the chances of the requirements just stated under (b) from being included in the thinking, the programmes and the policies of socialist organizations and movements. It thereby increases the chances of repeated moral and political failures such as we know enough about already.
(d) Evidence that human beings need, if they are to live well together in large numbers, restraints of the kind stated in (b) is overwhelming - pending someone somewhere coming up with something new in the way of relevant evidence.
(e) Utopian ideas about human nature that ignore this evidence are a political folly that has been far too costly in human life and human misery.
(f) A socialism that relies on wholly, or mostly, benign assumptions about human nature has, consequently, had its day.