In my opinion, police won't budge much unless a higher authority is pressing on them. It's not that they can't find the bike thief, they definitely can (and in a timely fashion). They simply do not care.

Banks seems to have lots of influence and move things around. Bank thefts (where I live) net for thieves around 10-20k USD. They get lots of police action. Other thefts with even higher amounts go unnoticed.