Actually, they all do -- or at least all those that were built in the last 28 years, since the American Disabilities Act (ADA) standards took effect in 1991.
According to the ADA, large hotels with between 501 and 1,000 rooms must provide at least 2% of their total rooms as accessible, along with four with roll-in showers (plus one roll-in shower for each additional 100 rooms over 400).
ADA-accessible bathrooms must provide a shower seat in all accessible rooms with a roll-in shower. In addition, water controls and a handheld shower nozzle must be placed on the adjacent back wall and within reach of the provided seat. Grab bars must be located on the side wall opposite the shower seat and also along the back wall. Grab bars are not allowed on the side wall to which the shower seat is attached.
Most pre-1991 hotels, even smaller ones, have retrofitted at least some of their rooms to be ADA compliant. Las Vegas in general, and the major and minor hotels in particular, have been extremely accommodating to disabilities since the Act passed.
So if you want a hand-held shower, you can request an ADA-compliant room and you'll have one.
Beyond that, hand-held shower heads have been popular in Asia and Europe for some time and are finally becoming a thing in the U.S. Americans have been introduced to them in their travels and Asians and Europeans often have an expectation of hand-held showers in their hotel rooms. So in addition to the ADA-compliant hotel rooms and baths, more and more hotels will be installing them in the foreseeable future.
