You're making this up, aren't you Balders? Your examples seem to conveniently to back your weirdo viewpoints up. And what the hell has 'institutional indifference to young working class men' got to do with it - the police are hardly set apart from that group, are they?
Trust me, once you're repeatedly stopped by police - and customer service and politeness isn't their usual strong point - then tensions begin to grate. I've lived here for over 30 years now and I can point to plenty of experience that it is largely as simple as that for many folks. Even if there was a level playing field elswhere, which of course there isn't, indiscriminate use of stop and search will lead to people's impressions of the law being coloured from an early age. Why respect a force that is rude and discriminatory to you from an early age and shows little sign of change. It's not just that of course, but it's difficult to underestimate just how much that feeling of resentment and unfairness sticks with you. Especially when it happens again and again, both to yourself and people you love.