It's a crappy situation, Skye, but there's no good answer. Prostate cancer in a man is an almost inevitable part of ageing; around 70% of 70-year-olds have it, 80% of 80-year-olds, and so on. The overwhelming majority of them will need no treatment and will die with prostate cancer, not from it.
If (as is currently the case) you don't screen, the result is that you'll probably only find those men who start showing symptoms (or, as in my case, if it's found accidentally with no symptoms).
If you do screen, firstly it would be enormously expensive (and unfortunately the economic cost of healthcare does have to be considered), and secondly, you'll treat a lot of men who really don't need treatment because they won't die from cancer. Current cancer treatment centres certainly wouldn't be able to cope with the increased workload of high numbers of millions of additional patients.
Which of these two options is less harmful to society? Rightly or not, the medical powers-that-be in this country have decided that the first is.
Best wishes,
Chris