We've got people on mopeds throwing acid around in London. People on dirt bikes throwing bricks in Birmingham. The police are always cautious about pursuing motorbikes because they don't want to injure the rider, and the criminals know this full well.
AIBU to want the police to just get tough and ram the feckers? They chose to get on the bike and run from the police, they should take the consequences. Not be free to ride off into the sunset and commit more violent crimes against the public.