I certainly have an interest in the court system of our country seeing as I work in it. However, I still think that this thread is a load of incoherent, disconnected nonsense.
However, to answer the original question, it isn't exactly rocket science is it? The majority of the crime that is prosecuted through the magistrates' court on a daily basis is the bog standard stuff that happens every day. The bulk of the MC work isn't murder and rape and fraud. It is shoplifting and low level public order offences and criminal damage. A lot of this sort of crime has a close correlation with financial deprivation. Therefore a high proportion of the people sitting in the MC on a daily basis are very low income/unemployed.
The mags court also deals with DV and drink driving which, as someone mentioned earlier, tend to be far more cross-class. Tower Bridge for example tends to see a lot of middle class professionals up for drink driving - I have dealt with several junior doctors from the local hospital for this offence.
The type of crime that is dealt with in the mags is the type of crime that is, for obvious reasons, less prevalent in people who have the means to get better paid jobs, houses outside areas of social deprivation, children in schools with few social problems etc etc. The middle classes still commit crimes - they just don't tend to be the grass roots stuff that is seen in the mags court every day.
It's got nothing to do with paying for a "better lawyer" either. The same lawyers do private work and legal aid work - legal aid lawyers aren't a special underclass for people who can't afford any better. There are a few specialists who don't do legal aid but they tend to be fraud lawyers. If someone isn't eligible for legal aid they have the option of paying privately. They still get the same solicitor.