@anildash @ernie In practice: Adoption of a new iteration of the standards is also piecemeal & voluntary. These standards orgs will tell you as much, & I have personal experience.
And one disagreement between me & Ernie (different perspectives) is that I don't see these gripes as the core issue hindering webfeed adoption. They'd be good to address, especially in the process of promoting the tech. Since I see the main hindrance being that noone's heard of it.