What has not been made clear in the vast majority of reports on this I've read or watched on video is the actual question George Osborne was asked - one has to wonder why.  The closest I can get is from this Telegraph article

http://www.telegraph.co.uk/news/uknews/crime/9972255/George-Osborne-criticises-Philpotts-benefit-lifestyle.html

"Asked whether the Philpotts were a product of Britain's benefit system"

If that was the question then his answer is far more understandable - "I think there needs to be a debate about the welfare state – and the way it subsidised the lifestyle of Philpott… The taxpayers pay for the welfare state, subsidising lifestyles like that, and I think that needs to be examined."

Also if you think on it then it wasn't George Osborne who was linking the actions of Philpott to the benefit system but actually it was the BBC interviewer and GO's comments were every bit as much a "response" as anyone else's.

This whole episode has been blown out of all proportion by newspapers and some politicians for their own political capital

It was good to see that not all politicians took the same tack - Harriet Harman, "It is absolutely understandable – when people limit their families to one or two children and feel they'd like to have a third but they can't afford it – the exasperation that people feel for the very small number of very large families that there are. But if you think of the Philpott family example, above all that was a problem of somebody who was just a criminal, a controlling person who was abusing everyone in their family as well as abusing the system. Fraud should be clamped down on."