I didn't say it has dawn soap. Just soap, technically detergent not soap but the ingredients are also found in soaps shampoos, etc. There are many types of Windex which contain a multitude of detergents as well as dyes and scents. Detergents can kill the bacteria we are trying to grow during the cycle.
Original Windex has a total of 3 detergents
http://www.whatsinsidescjohnson.com/us/en/brands/windex/windex-original-glass-cleaner
There are at least 5 additional products called Windex of which at least one doesn't even have ammonium hydroxide as an ingredient.