When I import a .obj model in Blender, textures are not integrated into materials. It seems that nodes “Image Texture” are not created.
The folder includes the file .mtl and the textures.
Just because there is a mtl file doesn’t mean it has been written correctly…
Open the mtl file with a text editor of your choice:
Does it really reference the texture file (something like “map_Kd c:\path_to_image_file\image.jpg”)?
If not there is nothing for Blender to import and you will have to assign the textures manually. Just checked: With a correctly referenced image texture Blender imports just fine.