Surfaces without DDSCAPS_TEXTURE can still be textured when used with a software device.
wined3d currently doesn't care about the bind flags for surfaces set with wined3d_stateblock_set_texture(), but we currently set the right bind flags anyway.
More saliently, I plan to change this fact, and internally translate those textures to SRVs, in order to simplify some internal code and make d3d1-9 support for the Vulkan backend easier. In this case we really will need WINED3D_BIND_SHADER_RESOURCE to be set.