This is what happens with you summarize an idea with a sentence that hits the key point - it is often weak and misses the supporting ideas. You know that I am not afraid to dump a wall of text to support an idea - just not every time I mention it in passing.
We have a long winded thread on intelligence vs consciousness and it is not topical to the original post - if you want to continue this idea I suggest that we switch to that thread but a short response is this:
I do.
In that thread there were several attempts to examine exactly what intelligence is. Most were a laundry list of traits that assumes that if you have these traits - you are intelligent. As you correctly stated above - intelligence is a continuum so you end up with a this multi-variate input function yielding a slope with no clear relationship between the factors in the definition and the result. It really misses defining the core of what intelligence is.
The definition I offer is simple and gives a general metric based on the concept that the purpose of having a nervous system is to select and perform some action based on perception. If you think about most measures of intelligence you can boil them down to measuring this exact thing. There may be internal factors that drive this selection of action but in the end - smart people understand what they are seeing and make better choices.