Too True. Policing, like so many Government activities, has become a 'numbers game' where the only thing to matter is the statistics.
Result is that coppers are reluctant to attend a street-incident at all, if it's unlikely there will be arrests to be made. Thus, the only crimes to get dealt-with are those where an arrest is likely. The others are allowed to continue unabated - even if the fact that a copper had showed-up promptly would have deterred a repeat.
The converse is also true, that the police will jump-on any chance to charge Joe Public with a crime, no matter how preposterous that charge may be. There is, after all, always the possibility that the poor sod will plead guilty, and if so, that's another one on the scoresheet.
This situation naturally plays right into the hands of minor crooks, yobs and ne'er-do-wells, who by making a trumped-up accusation or two against Joe Public, find it very easy to get the coppers inadvertently working FOR crime instead of against it.
Oh, and then of course there are the 'Bandwagon Issues' like 'Zero Tolerance of Violence Against Women!!!!' - Anyone reporting an incident in one of these 'politically correct' categories will have half the local force out, complete with white hoods, burning crosses, megaphones and of course the obligatory squadron of black helicopters. . Even if it turns out to be a pillow-fight.
Any wonder crime flourishes?