Coming to this conversation late, but still fwiw here's my view.
Think about why we have contexts. Its not for some arcane reason. It simply recognises that we may have upwards of 200 Next Actions in front of us at any given time. Contexts are just a way to break down that list a little so that we don't have to scan through all 200 every time. The easiest way to reduce that list is to ignore those we can't do, which is why context was always so helpful. Not at home? Ignore those. No Internet? Ignore those too, and so on.
if you have no contexts, you're just going to have to trawl through a long list of actions, and probably face either missing important ones, or just feeling overwhelmed about the whole thing.
Granted contexts will change over time (@Moon?). but the need to drill down your list doesn't change. Just the opposite, as we all take on more and more tasks (and know to define them as such) we need better ways to drill down than ever before.