Synthetic events violate non-bubbling event specification

[CITguy]

Do you want to request a feature or report a bug?
Bug

Current Behavior

Native blur and focus events do not bubble, but synthetic events for onBlur and onFocus do (which violates the non-bubbling event specification).

As it is currently implemented in React 16, onBlur behaves more like a native focusout event and onFocus behaves more like a native focusin event.

Demos

React 15 demo: https://codepen.io/CITguy/pen/gzzoQj/
React 16 demo: https://codepen.io/CITguy/pen/PeRRwz/

Expected Behavior

Synthetic events for onBlur and onFocus should not bubble.

Tested

OS: Mac OS 10.11.6 and 10.13.4 (no affect on bug)
Browsers: Chrome 66, Firefox 60 (no affect on bug)
React versions: 15.6.2 and 16.3.2 (bug present in both versions)

[aweary]

This is a known and intentional deviation from native event propagation behavior. It's possible this may change in the future. See #6410 for more information.

[CITguy]

@aweary: Should it be documented as such? https://reactjs.org/docs/events.html#focus-events doesn't mention anything about the focus and blur events deviating from native event bubbling.