I'm sure you must have noticed, Modeller, that only a few weeks ago there was a hoo-hah about an upcoming fuel-price increase...since abandoned temporarily. The Tories instantly bleated, "But this was an increase arranged by Labour, nothing to do with us!"
Presumably, they had lost sight of the fact that they themselves have been in power for nigh on three years and had exactly the same opportunity to alter earlier Labour policies as you say Labour had to alter Tory ones.
To paraphrase your final paragraph...
On a personal note I don't like David Cameron. I don't think he is a good Tory leader and, even if he dumped George Osborne who is plunging us deeper into the mire by the day, he wouldn't find any more favour with the middle ground electorate.
And as for my "repeatedly trotting out" political points, I suggest you examine such activity rather closer to home.