The "idiot-imbecile-moron" scale has not been used in clinical practice for many decades, because it is offensive, and deprecation of "retarded" (as a description of mental ability) from professional use followed shortly afterwards.
Moe Howard used those words interchangeably in the 1940s. I don't think he knew the fine distinction.
OMG !!! Someone actually stumbled onto the underlying answer!
This is what I'm trying to get across !!!!
The terms moron, imbecile and idiot haven't had reasonable use in clinical terms for decades.
But socially we accept them to describe things we find objectionable in some manner.
"Dan - you're being an idiot for doing that."
"Sally - you're a moron for thinking that."
"That is the most imbecilic thing I've ever run across; who would buy that product?"
Etc ...
No one blinks an eye at these terms, whether they are applied to a person or a thing. Sure, they are meant to be derogatory, but no one says we can't use them. Sometimes they are used in jest; one friend playfully teasing another. At times they are meant to be hurtful. When these words are used, they are combined and considered with the INTENT and CONTEXT of the message, and not solely on the words themselves.
But not the word "retarded". No sir. That's considered heinous all the way around. Whether you describe a person or a thing, in jest or in hate, it's completely vulgar to use this word. The context and intent don't matter when the R word is used. Despite the fact that it's really referring to the exact same topic conceptually as all those other words.
It just REEKS of hypocrisy; selective anger as I put in the thread title. Typically exuded by those who want to gain attention with their outrage. Outrage which has not basis in fact or logic. And that makes it VERY hard to understand what we can or cannot say, now or in the future.