Hotels have it even worse.
Most hotels don't accept pets. Flea and pet dander which set off allergies are the two biggest reasons. The cost in cleaning a room afterwords adds up quickly.
HOWEVER, if the person claims that the pet is their "support animal", the hotel is required by law to accept the pet and can not charge extra or even ask for proof. To do either can result in a lawsuit for violating the Federal ADA laws.
It depends on the hotel. The more expensive the hotel, the more likely it will accept pets. I have stayed at the Beverly Hilton and the Palomar with my dog as a welcome guest. Even in the restaurant on the patio.