The reason the sinks and toilets have their own valves is it makes life easier when repairs or isolation is needed.

The reason the shower does not have an integral stop (shut off) is because contractors when asking for bids want the lowest possible price so the plumber will not install the two valves @ $10 ea as they have to cut corners whenever possible.

There is something called "Tile stops" which are valves on the branch line right off the riser these two valves control the entire bathroom (UNLESS you have a flushometer instead of a low down tank)

These globe type of valves are used not only for throttling but all for a shut down of the entire bathroom.

Again this is something that is not installed in many one family homes as the builder and plumber want to get in and get out and let the next person doing repairs worry about climbing stairs to shut the water make repairs turn on the water and hope they made the repairs correctly or they have to walk down stairs again.

I have seen one valve on the hot water line controlling the dish washer and faucet or one valve used on a kitchen C/W supply for the faucet and ice maker.

They be out there, think of the $10 per valve times how many they do not install

thx kind of figured that but you would think... huh ? guess i will call a plumber then ....

In the last couple of years I have installed two shower/tub valves, single handle, pressure balanced.

They both had intergal stop valves. Remove the trim plate and the stop valves are on each side of the faucet and takes a flat blade screw driver to operate them.

Don't rember the brands.

Symmons comes with the integral stop GREAT BRASS shower body Delta like most other brands you have to ask for the stops

The are also pressure balanced and are cheaper then most brands when considering the stops are part of the shower body.

I do not remember the model number Sorry