Why can't political commentators do simple sums?

What is half of five? According to political commentators and analysts, it is one.
We are only a year into a five-year parliament yet everyone is describing the Conservative losses as the usual "mid-term blues".
Not only is this not mid-term, it should be part of that other psephological cliche, the honeymoon period. One year after Labour won in 1997, it managed to increase its number of council seats and councillors .
The Tory result is being presented as satisfactory for Cameron because anything looks good compared to what has happened to the Liberal Democrats and, naturally, their supporters don't want to accept that this is almost certainly the start of a very long slippery slope.
The cuts have hardly started to bite, there will be hundreds of thousands thrown out of work in the next few months and the economy is stagnant, with prospects of another downturn (why does anyone think that isn't likely when the Bank of England's monetary policy committee has again refused to put up interest rates, despite inflation running at twice its supposed level?)
Incomes have suffered their biggest decline for 30 years and house prices continue to plummet in all but the wealthiest areas.
The real test for the Tories will be in next year's local election and the year after. Unless the coalition collapses before then.