In Scotland, it is feared that taxes would rise as it is less prosperous than England. Therefore, this would lead to tough decisions, i.e. would university fees still remain free? This could thus adversely lead to greater restriction on the executive's taxational powers, therefore it doesn't seem worth the hassle if the only aim achieved is defeated once put in principle.
One of the arguments for devolution is that it brings the Government closer to the people, this would help to thus solve the "West Lothian Question" as it would mean the Welsh rule the Welsh and the English rule the English. This would be more democratic and provide greater choice of MPs to both the Welsh and the Scots however it will only create another layer of government and thus increase cost to the tax payer. In the current economic climate, this is not the most sensible economic move.
However, some people believe that by conceding devolution it will prevent the breakup of the UK as it will concede demands for full independence. However, as exemplified by the Scottish, once a concession is made, the greed for power takes over. This will break the British traditionary partnership that has remained successfully for centuries long.
As well as this, who will become the decider on the legitimacy if a referendum was to take place on complete independence. Who would draw a line that casts the referendum results as legitimate and those as not. If it were to be the English, they are likely to pose a high turnout, whereas Scotland and Wales are likely to significantly reduce the threshold.
However, different national regions have different needs to England, this would be greater reflected through a regional government. This would affirm the democratic principle of "government for the people, by the people". It will also reduce the workload of the British Parliament and government however, it will also lead to inevitable confusion as it is an additional layer of bureaucracy and method of government to get used to. The simple fact is that most people prefer the current system, people tend to be anti-change, as exemplified through the AV referendum.
Therefore, in conclusion, although in theory it would be better and more democratic to bring the government closer to the people - in practice, it just isn't practical. This is due to the heavy economic implications as well as the general confusion such a political change would incur. Small devolutionary steps are likely to pass off into leaps, as exemplified through the SNP's nationalistic ideologies. Their hunger for power, and the preservation of the UK is best controlled therefore by not devolving matters further. In the current economic climate, the change just isn't feasible and people tend to prefer the norm and are thus, anti-change.