Not to defend Boulder, specifically, but when thinking about regulations it's really easy to tally up "all" of the costs and benefits without crediting them for the nonexistent costs of the bad things that didn't happen.
2) Most cities fire code say that your backyard grill is required to be a certain distance from the building structure (my local ordinance says 15ft), it just so happens that most people ignore the local ordinances. Those codes are b/c of grill fires.
[1]: http://eresources.nlb.gov.sg/infopedia/articles/SIP_1637_201...
I'm not against regulation, I'm against broad, overbearing, and dumb regulation.
Just as a reminder: Up until the early 20th century, any large city that wasn't home to a Molasses-based catastrophe had at some point burned more or less completely down, usually killing thousands: Chicago, SF, London are well known.