Aren't all programs languages as the program describes a particular problem
or set of problems?  It seems that saying that a program is not a language
is a bit of an artificial distinction.  Mathematics is a language.  Ruby or
C++ are languages that can be used to construct entirely new languages.
 Even pictures can form the basis of language.  Every program that exists
possesses the vocabulary to deal with a given problem domain, so why bother
trying to claim that something like Excel does not have these qualities?
 Aside from adherence  to useless jargon of course.

As for issues like terseness, it isn't really a virtue at all. That you can
say or do more with less is not very important if people have a distinct bit
of trouble understanding what is being communicated.  The goal should be
clarity, not trying to condense everything into the fewest possible symbols,
ultimately to say that you could.