You can argue improving email shouldn't be a priority, but the proposal in the article has zero cost. It's a free improvement.
I have to say you've failed to articulate why making email better (while we work to come up with a better solution) is an inherently bad thing. Especially when we can make it better for free.
What we should be doing is making end-to-end encryption easier to use.
PGP & S/MIME failed at this completely.