In 20 minutes the cops would have came. This is an expensive lock, presumably for expensive bikes, which won't really be parked in low-income high-crime areas all that much. I.e, there will be security cameras, private security guards, and cops within easy reach. If these locks were popular, a thief could steal them very many of them before anyone gets suspicious. If you are only stealing the bikes that are worth in the thousands, you could steal enough in just one month to have a nice income for the entire year. That's much less chances of getting caught.