I think when folks say "not a quilt" they are referring to any other article than something you lay on a bed. So, if they've pieced and quilted a purse, it is "not a quilt" or if it's a table runner, still "not a quilt".
I don't think that it has anything to do with whether or not it's art, etc.
And a wholecloth not being a quilt? LMAO! That's like debating whether the sky is blue!