Utopian goals are very nice. They are important to the uplifting of humankind. But let's get some engineering practicality into the discussion. First, any existence on Mars will depend on high technology to maintain life. Sustaining air, water, food, and mobility about the planet Mars can't be built up as humans did on Earth over thousands of years of our history. Agrarian farmers eking out a life of growing their own crops and livestock cannot happen on Mars. Martian life will depend on technology. What do you need to establish an independent, self-sustaining and technological civilization on Mars? Here is my short list. Try to imagine all of the following needs, but without resupply from Earth. Start with resources for manufacturing all items. Metals require sources of ores. Can we locate and exploit on Mars large deposits of copper, iron, aluminum, trace elements, etc, Where will you find those on Mars? The ores will need processing in factories, usually using huge amounts of energy, and using large amounts of other resources. Where will Martians find Gigawatts of electrical power? Solar? Plastics, electronic circuit boards, LED lamps, fertilizers, and fabrics require sources of hydrocarbons, usually from petroleum or natural gas. Where will you find those on Mars? How are you going to manufacture the range of microchips needed to maintain the existing electronic and digital equipment that you will rely on for survival? Surface or subsurface transportation and mobility are key to establishing any technological economy. Agriculture: where are you going to farm crops and livestock on a scale large enough to feed thousands, and then millions of Martians? You'll need millions of acres of crops and livestock. And people, equipment, and methods to harvest, process and transport them to the consumers. Then there is construction on Mars. We will need to map out where and how to build the foundations for building structures. Foundations that will have to survive decades of gravity loading on the Martian soil and rock. But, where thousands of people gather to live, there will be spills of liquids such as water, fuels, chemicals, wastes, etc onto the ancient soil beds of Mars. These ancient soils have been desiccated for billions of years. What do you think will happen to your structural foundations after some top layers of Martian soil becomes damp from water discharging, having not been exposed for those billions of years? It will seriously alter the strength and behavior of the soils, and that will seriously jeopardize the structures on Mars. Collapse is the immediate risk for any building on Mars, or any road or railway roadbed. These are structures that are needed for survival of the Martian population. These problems can be solved. However, solving these problems will take generations, decades, probably centuries. Building up a base of knowledge of what works, and what does not (remember all the catastrophic failures throughout human history on Earth). During those generations who are learning how to live on Mars, the Martians will continue to rely solely on resupply transportation from Earth. Millions of tons of resupply, constant resupply. Then there is the problem of waste handling. Where will the manufacturing and other waste be deposited on Mars? Few of these problems would be solved by the so-called "terraforming" ideas. More utopian dreams.