AOG, stop being so obtuse. You're deliberately misinterpreting what people say.
All SP's said (and correct me if I'm wrong here, SP) is that the reason the people you've categorised into the amorphous 'left' haven't given any answers is because they don't know them - because it's a very complicated issue and they'd rather not just dive into the most simplistic answer available. (Well, either that or they can't be bothered).
He gives a parrallel with asking about white paedophiles - fact is, we don't really what causes this just as we don't really know what the causes are for the issue you've raised. The reason for this being that there isn't as much public interest in really analysing the problems/causes as there is in something like, say, crime - I'm sure there are some experts looking into these things somewhere around but the public generally aren't as interested in their findings.
Upon reading this, you've rolled your eyes and gone 'Gah! Liberal Conspiracy!' which kind of misses the point, to be frank.