Comparison: you are angrily maintaining "Orange is a colour! It is right there in the rainbow! Red, orange, yellow, green, blue, indigo, violet! It's a colour! That is the set to which it belongs!"
It is true. But it is incomplete.
It is also a fruit. It belongs equally in "apple, orange, banana, pear, quince."
Also a valid set; no parallel.
It is in other sets too. The set of citrus fruits. "Lemon, orange, lime, pomelo, grapefruit."
Oberon is a programming language.
It is also a set of frameworks. They are integral.
It is also an editor.
It is also a UI design.
It is also an OS.
Any one is true but is incomplete.
There are other views but yours and none is privileged; yours does not invalidate the others, nor they yours. You only see one but your view is too narrow.