I just read your views on coloring books and I'm compelled to respond. I myself am about to publish a coloring book and I'm proud of my efforts to make it worthwhile and enjoyable to whomever may choose to color it, whether child or adult. I do agree with some of your statements if they are applied to coloring books that contain realistic images (such as a dog or a car, or marketing ploys like mickey mouse) because they require little imagination to color. I do have a great deal of respect for abstract images as they leave those who color them freedom to respond to their own instincts and their own tastes, as well as teach them about color relationships and form. It also makes them aware of their taste or style and hones their ability to explore it on a blank sheet.
I have my opinion, you have yours and everyone else has theirs - some people will color coloring books and others will do other things. Who are we to decice what gives them joy or inspiration?