The SMOG calculator doesn't automatically tell you if something is gibberish, in that it is reasonable to use complex language in order to increase the precision of what you mean. That's the trade off a writer (who wants to be understood) must balance - precision vs complexity. Writers of gibberish deliberately minimise precision by increasing complexity. The hope is we won't understand they have nothing to say; moreover, given the complexity we'll think we just aren't clever enough to understand what they are saying. Clear writers, on the other hand, only increase complexity when there is a marked and necessary increase in precision.

For example, consider this from an older post on gibberish:

The criticism of our time... is indissociable from an investigation and experience of its transcendental field(s), of the (impersonal) tendencies and haecceities which traverse it, as well as the potentialities, utopian ones perhaps, with which our present can be composed. This 'geological' aspect of 'total critique' is of course essential to a dislocation of the present as atrophy and stultifying repetition of doxa.SMOG grade of 18.97 = post graduate degree required.

"The 'geological' aspect of 'total critique'...". lol. Compare this to the wikipedia entry on Quantum Electro Dynamics. Even though you might not understand the terms used, it's still clear the paragraph actually means something. The complexity is due to the necessary use of precise technical terms - quantum mechanics is bloody technical and complex:

Physically, QED describes charged particles (and their antiparticles) interacting with each other by the exchange of photons. The magnitude of these interactions can be computed using perturbation theory; these rather complex formulas have a remarkable pictorial representation as Feynman diagrams. QED was the theory to which Feynman diagrams were first applied. These diagrams were invented on the basis of Lagrangian mechanics. Using a Feynman diagram, one decides every possible path between the start and end points. Each path is assigned a complex-valued probability amplitude, and the actual amplitude we observe is the sum of all amplitudes over all possible paths. The paths with stationary phase contribute most (due to lack of destructive interference with some neighboring counter-phase paths) — this results in the stationary classical path between the two points.SMOG grade 15.07 = some college.

A bunch of wikipedia writers can explain some of the most complex physics going using less esoteric terminology than an archetypal continental