“lazy and disinterested”
There are 122,000 police officers in England and Wales, of which 113,000 (Source: Home Office) are sergeants or constables doing useful, non-admin work. 20% of police work is solving crime (source: HMIC). That gives you 5 million days/year available.
There were 6 million recorded crimes per year (source: ONS). Failing to stop is not a notifiable offence so not in that 6 million. Each crime therefore gets 5/6th of a day to investigate, prepare a case and prosecute. Just turning up to court will take a whole day. Clearly there has to be some prioritisation.