It seems inconceivable, to bicycle manufacturers, that I want to tour or commute with a racing bicycle, rather than buy a separate bicycle for touring.

Aside from this, there is the issue of sizing the rider to a bicycle frame.

There really isn't a need for bicycle frames in 2 cm size increments. A consumer made to think that they need a particular frame size will lead to greater sales as consumers will have more difficulty finding options in the used bicycle market.

Also, they will try to fit you on the largest size bicycle that you may be comfortable riding, for the purpose of market segmentation. Larger frames can be ridden by a smaller percentage of the population. Less choices in the used bicycle market for consumers.

Apparently, it is easy to brainwash the bicycle shops.
“ The typical LBS pushes new riders toward large frames with short stems, mainly due to the taller head tube “
” The problem is, we want to be comfortable, because riding shouldn't be torturous. Guys whose only job is to go fast eschew such concerns-- there are 6' tall guys on the Tour riding 54 and 52cm frames. ”

He says torturous because of the lower height of the head tube, however I find having the handlebars lower to be more comfortable, because my arms are extended with only a slight bend at the elbow. With high handlebars I'm holding up my weight with very bent elbows.

Tour de France cyclists are also comfortable on small frames. reddit

For very short cyclists, who would benefit from using smaller diameter wheels, you will only be able to find one, or maybe two, medium width 650C tires (ISO 571mm diameter) still in production (see Team Estrogen for 650x28mm or above).
You will likely not find many narrow or medium width 650B tires (ISO 584mm diameter) (see 650B Palace for sizes below 32mm or 1.3“). Having less wheel sizes reduces manufacturing cost, as only one set of machinery is needed for bicycle frames and wheels. Since a road bicycle is a road bicycle, no greater profit is made by having the choice of a smaller wheel size.

For mountain bikes, different wheel sizes are marketed as meeting specialized needs, duping the consumer into purchasing multiple bicycles for different terrains.

For road bicycles, bicycle shops will fit you on a larger frame than is comfortable. Smaller cyclists, for lack of bicycles with smaller wheel sizes, have to ride a bicycle with improper geometry (see http://www.rodbikes.com/articles/700-compromises.html).

It's not about choice, it's not about customer satisfaction. It's about fooling the customer into spending more and increasing profits by reducing manufacturing cost.

https://roadcyclinguk.com/gear/buyers-guide-go-tubeless.html
“Manufacturers need to invest the time into developing the technology,” he adds, “but probably won’t do this until a desire to invest time into learning the system is expressed by the rider. That leads to a comparative shortfall in the availability of the year-round tyres a great proportion of road cyclists use.”

For an almost negligible gain in rolling resistance, manufacturers are the driving force to further segment the bicycle industry. By introducing incompatible technologies, less parts and bicycles are re-used, which drives up the demand for new bicycles.

When coming across bicycle forums on the internet, I wonder how many users are actually corporate employees, paid to express their “real life experiences”. I wouldn't put it past some corporations to do this.