Because deserts are hot and most people probably do not like hot weather and also their is not a lot of water supply.
Most people who live in deserts live there because they like the desert. I live in a desert and love it.
Most people who live in deserts reside in towns and cities.
Nearly the entire state of Nevada is covered by deserts.
Most Egypt people live in the Nile Valley not the Deserts because there is more water supply and it isn't that hot in the Nile Valley as it is in the Deserts.
It is very dry and hot. People can't live in most deserts
Yes, many people live in the deserts of Africa.
Austria has no deserts.
By 'they' I assume you mean people. Yes, millions of people around the world live in deserts, including the author of this answer.
The least people live in the deserts in the South or on the mountains.
Millions of people around the world live in cities and towns located in deserts.
Most children attend schools just as they do elsewhere in the world. 99.999% of people who live in deserts live in cities and towns and most of those have schools.
Roadrunners are most commonly found in the Chihuahuan, Sonoran and Mojave Deserts.