The bulk of the criticism from rational people that I hear is due to the "but they do need to adapt" argument. Flagrantly violating the law just because you want the law to change is not the proper way to do this. If Airbnb wanted to form this industry and generate revenue for cities and offer protections for renters, rentees, and residents in the buildings the units reside in, they would attempt to change the law through legislature. The fact that they simply keep raking in profits from users obviously violating the law paints them in a very negative light to any rational resident of a city where Airbnb is illegal.