[playpause]

My feeling is that the 'undermining' the author refers to is not a conscious attempt to keep the lower classes down. It's just middle/upper class people spouting fashionable political views, going along with the 'right message', and not really thinking about it. When it comes to their own personal behavioural decisions that will affect their kids, they take it more seriously, basing their decisions on their deep-down sense of 'how things really are', and then they come up with some kind of rationalisation of how this conservative behaviour actually fits in with their anti-conservative political views. This rationalising process has become second nature and they don't notice they are doing it at all.

[raxxorraxor]

It is also often of form of courtesy. You don't want to burden single parents further by elaborating how damaging this can be for their kids, especially if you have them in your audience and it makes it even worse if they take it to heart. So in that situation being polite and being honest collide like in many situations. There are some true believers, but they are far more rare.