why Vehicle subClassOf Product ? (also: Commercial, Economic)

Hello,

As I understand Product acts as Class for adding e-commerce aspect to
other Things. Most likely to use it with "@type": ["Book", "Product"] or
additionalType when used in microdata.

I don't understand why Vehicle landed as subClassOf Product? I also
don't understand which other things may end up subclassing Product in
the future and which will for example subclass CreativeWork or Place.

IMO Vehicle, just as Place could directly subclass Thing. Or we could
also add Tangible class to deal in a future with with Device etc. (e.g.
http://schema.org/MedicalDevice)

It reminds me about my question long time ago about POI (Point Of
Interest). Which also doesn't make that much sense in class hierarchy
but could similar as Product serve as a class to use in addition to
other classes.

I haven't worked with ruby programming language for quite some time, but
in some ways I see similarity to Class vs. Module (besides many other
differences from Object Oriented Programming, single parent doesn't
apply here as well)
This answer has relevant example which happens to use a Vehicle
http://stackoverflow.com/questions/1282864/ruby-inheritance-vs-mixins/1282895#1282895

In a way Product sounds to me as something more in direction of
'Commercial' or broader 'Economic'.

Thoughts?