Many people (including some popular stylists) think that all hair types should be maintained the same way, and think that one hair type is better than the others. Imagine treating cashmere, silk, even linen, the same way as polyester or polyester blends!
Therefore, learning how to maintain hair type 4 (a,b,c) goes to the end of the list or has to be "restructured" into another hair type.
In reality, this hair type is one of the easiest to manage. I've met many ladies with all hair types who told me how healthy, voluminous,and pretty my hair was, AND how they wished her hair (mostly straight) was like mine. Of course, I used the opportunity to tell them how I maintain it, and they are surprised of what little I do.
Until enough people with type 4 hair embrace it, and refuse to compromise its integrity for any reason, the question the OP prompted will always be a controversial subject, and necessary.