Who said anything about boxing your tooling in to SDN tech? You
> described Software Defined Networking as a rabbit hole and snake oil.
> It isn't. It's a class of tools in the networking toolbox and an
> increasingly useful one.
My toolbox in the garage has torque wrenches and allen wrenches and a GS-911 for talking to the Motronic on my bike, too. It's a pretty useful toolbox. I use all of them. I don't keep them all in the same drawer of the toolbox, though. Guessing you don't either. Or if you do, I *probably* don't want you working on my bike.
I for one would be happy if someone came up with some different acronyms and subdivide the "world of SDN" into some number of sub-techonologies/practices that were at least a little more cohesive with each other so then at least we'd know what keywords to fit into our news feeds so we could pay better attention to the bits that are more relevant to where we are. Ansible/netmiko/<whatevertoolset>+CI/CD applied to kit (and people) does not resemble OpenDaylight or what hyperscalers are doing with DPDK on cards or the Microsoft FPGA-NIC trickery except in the broadest of views. All are good. Sure, they all belong in the toolbox. But maybe not in the same drawer.
As it is, we have marketing people sticking "SDN" onto every bloody thing that comes along in the hopes that it'll better catch the attention of someone without enough of a clue that they'll cough up (and leave someone else to figure out what to do with it). I freely admit that's just what they do and expecting them to do anything different is wishful thinking, but I don't see any of us doing anything about it except creating long email chains wherein we just keep trying to munge apples and oranges together. 
-bacon