Does JS bound to <element> need to inherit from HTMLElement?

While I completely understand the beauty of having any JS object bound to
an <element> inherit functions that make that object 'be an element', I'm
unsure of the practical value.

To me the critical relationship between the JS and the element is JS object
access to its corresponding element instance without global operations.
That is, no document.querySelector() must be required, because the result
could depend upon the environment of the component instance.

Whether that access is through |this| is way down the list of critical
issues for me. Given a reference to the element I guess I can do everything
I want. In fact I believe the vast majority of the JS code used in
components will never override HTMLElement operations for the same reason
we rarely override Object operations.

So is the inheritance thing really worth the effort? It seems to complicate
the component story as far as I can tell.

jjb