It's because as per your example, the government has no regulatory oversight on dressing rooms.
They do (through the Department of Agriculture) have oversight on amusement rides as a matter of public safety. http://codes.ohio.gov/orc/1711.551v1
1711.551 Duties of riders.
(A) No rider shall fail to do any of the following:
(1) Heed all written warnings and directions that require a person to meet certain conditions or to refrain from certain actions regarding an amusement ride, as determined by rule by the director of agriculture;
(2) Refrain from behaving or acting in any manner that may cause injury or contribute to injuring himself or other people while occupying an amusement ride.
(B) The director, in accordance with Chapter 119. of the Revised Code, shall adopt, and may amend and rescind, rules governing the types of warnings and directions required to be followed pursuant to this section. Rules adopted by the director determining the types of printed warnings and directions shall include specifications as to the character, size, and print size of such warnings and directions. At a minimum, the rules shall require the following:
(1) The warnings and directions prominently disclose the penalties imposed if a rider violates section 1711.551 of the Revised Code;
(2) The warnings and directions be based upon the standards of ASTM or the American national standards institute, or any other principles, tests, or standards of nationally recognized technical or scientific authorities that research the proper use of each amusement ride and the potential injuries that occur or are unique to each amusement ride if it is used improperly;
(3) The owner of the amusement ride display the warnings and directions in a public and conspicuous place on or near the ride. The penalty is covered by http://codes.ohio.gov/orc/1711.99 (C) Whoever violates section 1711.551 of the Revised Code is guilty of a minor misdemeanor; on each subsequent offense such person is guilty of a misdemeanor of the fourth degree.