Play football where exactly? In the Territory of the gangs you want to avoid, you'll be knifed before you set foot in their park. Riding around on bikes is equally pointless, they want that bike and you're trash to them if you aren't a part of their crew.
This culture has festered for so many reasons, i'd actually have to write a paper to really get the point across, but frankly it's all down to a collapse in policing, a collapse in social programs for poor neighborhoods and a collapse in school funding. The lake of wages since 2008 versus the increased cost of living has also upped the stakes of everything when it comes to the risk/reward assessment of wasting away in a pointless retail job that's probably going to disappear anyway when the High street fails.
We already know from Glasgow's past that the violent solution did sweet **** all as well, it just hardened the kids into even more serious criminals.