It also, though, makes me think about whether technology has progressed by adopting Kubernetes, or if we've just made things more complicated.
Reading through the discussion, it doesn’t look like it was quashed; the project owners had a reasoned debate about the pros/cons of what would happen if such a support was included at the time and its a totally reasonable argument to me.
Replicating the capabilities it provides in another system that offers such capabilities wouldn’t involve less complexity. In fact, I would argue that the way the authors reasoned through the issues was made possible because they were able to operate with these abstractions. Imagine doing this but with eg AWS NLBs. This team might have discovered similar quirks in that setup. But now their knowledge and what they could share would be restricted to AWS NLBs. Since they’re working with K8s, the lessons they learned are a lot more widely applicable.
Another thing to consider (as pointed out by a sibling) is that an average user of k8s may not likely have to worry about minimizing 5xxs during application termination. But if they did want to, now they can.