Sure, that is really a variant of what I said - that severity of penalties probably does not have much deterrent effect since so many people who break the law seem to assume that they won't get caught. You are, I assume, suggesting that there is little deterrence because there really is very little chance of getting caught. I went a bit further and suggested that even if the reality were that they were quite likely to get caught, many of them would probably continue to believe that "it )getting caught) was not going to happen then.I think the fear of getting caught is the main deterrent, so, if there is no chance of getting caught unless someone dies then there is hardly any deterrent.
The only attempt at a solution would presumably be to first change 'the system' so that many did get caught ('much more policing') and then to prosecute lots of people and give them 'substantial' (but not draconian!) sentences and widely publicise the fact that such was happening. It is just possible that at least some would then realise that 'they might get caught', and hence feel somewhat deterred. However, I'm not convinced that even that would change all that much. A substantial proportion of murderers, bank robbers, rapists etc. do get caught, followed by high-profile trials, but that doesn't seem to stop a good few others continuing to believe that they will not get caught.
As stillp has pointed out, much more important than that would be prosecution for non-compliance with Part P - and such non-compliance could presumably be argued in relation to almost any type of 'electrical incompetence'.After all, the only illegal electrical thing one can be charged with regarding installations is not notifying the LA for very few types of work.
Kind Regards, John