I did not say "good/bad". I said "perfectable humans". While I may not have been using the best term, it's certainly not as simple as "good/bad".
Waht I meant to say is "most humans, when left to themselves, without daily repeated conditioninig and without daily repeated moral struggle, have the tendency to do the right thing (whatever the ideology in question considers the right thing)".
For example:
Humans, in mass, when left to themselves, tend to devote their life to study and observation of Torah. (counterexample - Judaism does not say this)
Humans, in mass, when left to themselves, tend to love their neighbors as themselves. (counterexample - Christianity does not say this)
Germans, in mass, when left to themselves, tend to be the Wonderful Arian Beings. (not sure where to put this one - the system collapsed not because they failed to be Perfect Arians (and yes they did fail), but because it was limited to Germans only)
Humans, in mass, when left to themselves, tend to live for peace and longevity.
Humans, in mass, when left to themselves, enjoy production and will be happy to satisfy others' needs.
Humans, in mass, when left to themselves, tend to rationally consider the rational world and deal with other humans on the rational, long-view basis. (this has never been attempted in reality, but an adherent of this one recently remarked that Govt should not send money to tzunami victims)
Is this sufficiently nuanced for you?