The global upgrade is required for all full nodes in both types. If a full node doesn't upgrade then it no longer does what it was designed to do; if the user is OK with that, they should just run an SPV wallet or use blockchain.info or some other mechanism that consumes way fewer resources.

But if you want the software you installed to achieve its stated goal, you must upgrade. There is no way around that.

Jorge has said soft forks always lead to network convergence. No, they don't. You get constant mini divergences until everyone has upgraded, as opposed to a single divergence with a hard fork (until everyone has upgraded). The quantity of invalid blocks mined, on the other hand, is identical in both types.

Adam has said "there is actually consensus", although I just said there isn't. Feel free to say what you really mean here Adam - there's consensus if you ignore people who don't agree, i.e. the concept of "developer consensus" doesn't actually mean anything. This would contradict your prior statements about how Bitcoin Core makes decisions, but alright ....

Finally John, I fully agree with what you wrote. Debates that never end are bad news all round. Bitcoin Core has told the world it uses "developer consensus" to make decisions. I don't agree that's a good way to do things, but if Core wants to stick with it then there is no choice - as I am a developer, and I do not agree with the change, there is no consensus and the debate is over.

Hey, I have an idea. Maybe we should organise a conference about soft vs hard forks. Let's have it down the road from where I live, a couple of weeks from now. Please submit your talk titles to me so I can vet them to ensure nobody does an offtopic talk ;)