There is definately a difference imo. For instance my hair look absolutely nothing like yours and as such would definately respond to hair styles, techniques and products differently.
I honestly feel like people with 4 type hair are the main ones who have a problem with people differentiating hair types because they want to pretend all hair is the same in order to diffuse the fact that their hair type is kinky in texture.
Is there anything wrong with kinky or type 4 hair? Of course not. Do a lot of people believe there is something wrong with it? Unfortunately based on what I've been seeing around these boards, I think so.
I haven't said much about it before but it's honestly pathetic imo. It just reads I hate my black self