[IshKebab]

Well I guess it isn't quite as simple as I implied.

The handlers don't know anything about HtmlHandler, so you are free to make OtherHtmlHandler or whatever. The dependency direction is correct, whereas with self-registration your handlers now depend on some single unique global registry. HANDLERS_BY_NODE_NAMES doesn't affect any other code that might interact with the handlers (tests is normally the big one).

barrkei gave some very good reasons to avoid self-registration.