I can understand hotels having a legitimate objection to the differential regulation that gives Airbnb hosts a cost advantage, but there are good reasons for exempting (some) hosts: generally, once you run a business at scale, there's a disconnect that leads to cutting corners with safety, which is what prompts these regulations.

If a hotel room is just one of a thousand properties (the thinking goes) then the owner might be too casual about safety issues -- hence regs to force them to care. But if it's a room in the owner's very own house, there is no such "incentive incompatibility": a fire is much more than just a financial loss for them, so -- if anything -- they're overcautious! Thus, it's reasonable to exempt the renting out of one's primary residence from these additional safety regs.

With that said, your general point still stands: many of these hosts are "superhosts" who rent 3+ properties, which does (from the perspective of regulatory concerns) look like a hotel business and which therefore does merit similar regulation.