I don't know if I'd agree with the article about changing the succession laws when it says that 'Great Britain's culture is so steeped in tradition that a push towards equality is a pretty big deal.'I think if you asked the average Brit they'd agree that the law needs to be changed. I certainly think it's absurd that it hasn't been before now!
If asked most of us would say 'yeah it should be changed' (except the author of Downton Abbey who's outraged by it!) but we also have a lot more to worry about than changing this particular law. However, it's not down to the average Brit, it's gonna be down to the average Canadian, Austrailian, New Zealander and so on. The cynic in me would suggest that Cameron wants this changed so he has a basis for changing the aristocratic inheritance laws, this would mean his wife could inherit her father's title (and Julian Fellowes could be an Earl instead of just a Baron!).