I think the analogy of the credit card fuelled lifestyle is a pretty good one.
I think that there was a sense in the country that we needed to stop spending and dump the card (or make cuts and eliminate the defecit) and the Ories are the party known to do this. They are in, and the cuts are in, because the majority of electorate knows this (and even at the local election, more people voted for a coalition party, not the others).
As pointed out, the cuts agenda is inevitable. No one would believe a party now who said it wasn't necessary. Ireland's austerity measures haven't yet totally save them, but (unlike southern Europe which didn't cut effectively) they are no longer in the most vulnerable condition.
I don't think, until we actually see a country default (eg pensions, benefits, public sector wages unpaid, services just halting) that we shall truly appreciate how damaging this debt crisis is.
The problem with the coalition is that, even in the post-electoral optimism when the cuts agenda was expected and likely to be supported, they made a total mess of it. Even though some of the worse examples do not get the airtime they should, the debacle of the CB inequalities brought home to many the total absence of fairness and continuing administrative incompetence (something more associated with Labour, but now lost all-round, it seems). And they keep stacking up more examples of incompetence.
Their support will however hold up, as there ream ins no credible alternative.
Sadly, nothing worthwhile has emerged thus far from the Labour conference - increasing public spending (the fees cap) hasn't won them much positive comment - it is too obviously an attempt to buy off an interest group (parents of 14 year olds?). And the "tax the banks" rhetoric won't cut it for much longer - given the roles that some of the stronger banks will be required to take in the Eurozone crisis.