It is, simply, that this Government has no concept of joined-up thinking and no real sense of forward planning. Looking at each of these four problems in sequence, it is clear that the same basic problem underlies them all.
First with the prison problem, this Government has greatly restricted the freedom of judges to set non-prison sentences over a wide array of crimes, as well as introducing an enormous number (did I hear 3,000?) of entirely new crimes. The result of this (and for the sake of this argument it is irrelevant what the merits of this policy are) has inevitably been a substantial increase in prisoners. If you create new crimes, and simultaneously make it more likely that a convicted criminal will go to prison what other possible result is there? So, Government policy created a substantial increase in the number of people going to prison. At the same time there has been almost new increase in the number of available prison spaces. A massive increase in demand for prison spaces and no concomitant increase in supply. And people are surprised there's a problem?
Jack Straw's comments on the niqab, commented on exhaustively by almost everybody, were, in essence, a lament for the fact that one certain separate cultural group is resistant to assimilation, and, indeed, flaunts its rejection of 'our' values. It is at least arguable that this is a result of the mass expansion in immigration to Britain over the last decade. Again, one can argue over the merits of large-scale immigration, but once that had been chosen as a policy (whether voluntarily or by default) there were always going to be cultural repercussions. To pursue one policy without addressing the inevitable results is to ignore the fact that actions incur reactions.
With the smoking ban kerfuffle I would direct you to DK's eloquent denunciation, and re-iterate his point: there is a law of unintended consequences; there should be a law of eminently foreseeable bloody consequences as well, and I know which category this mess falls into.
Lastly with the army payments. This Government has sent British troops to war more frequently than any other. Six wars of varying intensity have been fought under its auspices, with no guarantee that more are not on the way. A parallel can be drawn between Labour's view of the State as a vehicle for social change, and the British Army as a force for global change. However, in the case of the State they have jacked up its funding through higher taxation (the bastards) whereas with the Army budgets have been cut even as demands have risen. Understandably morale is through the floor and squaddies are buying their own boots and nicking MREs of the Yanks. In these circumstances a bonus payment is like sticking an elastoplast on a boil.
The common feature is that the Labour Government simply aren't very good at governing. They don't think through their policies, they don't plan ahead enough, they don't draft their laws carefully enough and they haven't realised that back-of-fag-packet policy making designed to win a headline is perfect for opposition and disastrous for Government.