Lets enhance Neutron API to make it flexible so that newer networking use cases can be accommodated.
More specifically, remove the inter-dependency of network, subnets, and ports upon each other. One should be allowed to create any of these resources independently without forced to create higher precedence resource. For example, one has to create a network first in order to create a port (neutron port-create). This forces the back-ends/plugins/drivers to create dummy networks in many instance to be able to create ports. This creates a scale issue.
If we removed these inter-dependencies by making these resources as optional attributes, one should be able to create a port first, and then, depending upon the applications behavior, be able to attach this port to a network. By making these as optional attributes, we keep the API backward compatible while making it flexible for newer use cases.
Please elaborate on your proposal. Creating a network creates no scale issue as without subnets networks are just weightless logical objects.