No, what I mean is that the rules are only at best heuristics for mimicking another style of writing. They're not correct or incorrect, except so far as they are poor representations of some specific culture.
To say there are formal rules of language is a bit like saying there's only one culture that is fit to judge the acceptability of your words.
(If that isn't what you mean, then what do you mean? That linguists should carry on, but not look for patterns and rules? Then what, instead?)
Also, what is a "linguistic construct" if we don't have formal rules? Whatever it is, wouldn't it be less ironic to call it a "speaking thingy"?