grown-up
BD, you were doing well until this point. It's a phrase that is so often used by Politicians (and I use it as a proper noun deliberately), but is quite meaningless. It's up there with "proper debate", which is usually a Politician's euphemism for "let's put off talking about it until you agree with me".
I understand your view - essentailly, this is a sideshow distracting us from more pressing concerns but, nonetheless, it may have the same effect as if we as a nation had engaged more fully on some more complex moral and social elements of the various New Labour governments' policies since 1997. That effect being the removal of them.
Now, what will we be left with? A moral vacuum, for sure, but that is the trick of our two party system: for so long as there is a distinct them and us, Government and Opposition, then we will continue to be distracted by the petty squabbling. Sadly, though, it suits our national mentality - seething anger and dispropotionate frustration at small things.
So, for me, it is only important because it has become important. It represents the divide between the "ruling classes" and the "ruled". Sure, twas ever thus, but that doesn't mean it ought not to be changed. The trouble is, there is a distinct impression of a "clinging onto power" here, and the role of MPs expenses - and more so gov't minsters - is indicative of this divide.