No, its not about taking money from people. The masses are too stupid to use distilled/deionized water. It about the lack of common sense of the typical consumer. And, many don't know math well enough to mix it correctly 50:50. These same consumers reproduce and vote. Make you wonder why the world is the way it is today. Every product sold needs to be idiot proof.
Another great coolant to use is Peak Global Lifetime. Its available full strength so that you can mix your own. Should be good for normal 3-5 year 50k-100k change intervals, whichever comes 1st.
Peak Global Lifetime is available full strength for us, and also premixed 50:50 for the other 75% of the population
My antifreeze recommendations are: Zerex Asian & Peak Global Lifetime
My personal change intervals(never flush) is usually 1/2 of what is recommended by whats on the bottle, or owners manual.
Here's your typical well or tap water scenario: