I didn't say it was a reason to "decide" on a programming language. I started with a premise and then said "here's my take" but nowhere did I say "this is my take on why you should use K/J/APL for real work." It's just a list of bullet points about why J (in my case) is interesting.
I said it was impossible to quantify, not that it should be quantified.
In general I just don’t think it’s a reason to decide on a programming language.