In order to comply with the bylaw, they would need to hire someone on-call who could respond to emergencies within an hour, and who could check the carbon monoxide and smoke detectors after every stay.

Wow, you mean you need to have someone who can actually respond to issues, particularly in a time-sensitive manner? Imagine that.

Hotels/Motels have extra fees they need to pay to the municipality, why should short term rentals be any different?