(1) Statisticians predict where crimes are likely to happen for the police using data.
(2) Police predict where the crimes are likely to happen using highly biased guesswork.
The statisticians are being irresponsible pushing the police towards (2). Option (1) can be de-biased, can be debated, its effects can be assessed and its parameters can be tweaked over time.
This is a choice between two options and the people signing on to this letter are arguing for the worse one. They link a bunch of news articles, but the academic complaint seems to be that the model says "assume crimes happen in high crime areas". That isn't a very scary model, and if anyone has an alternative they should be pushing it towards the police, not holding it back.
Just because they choose to "opt out", it doesn't mean everyone else will. It leaves the task to a smaller pool of competent people (best case), or unscrupulous people out to make a quick buck or push an agenda (worst case).