I appreciate your opinion, but can cite myriad examples where your suggestion would be misleading. The Flesch-Kincaid scale weighs heavily on syllables to determine grade-level equivalent, How many multi-syllabic words do you hear in advertising copy or in popular music?
Or take music for instance: This is the refrain from one of my favorite Ani DiFranco songs:
"first you go under and then coming up gives you bends and when you break the surface and all you see is your friends."
And here's the refrain from the #1 song in country this week, "Blurred Lines;"
"and that's why I'm gon' take a good girl, I know you want it, I know you want it, I know you want it, You're a good girl"
Qualitatively the difference is vast, as is the success of each song. They're inversely proportional.
I think you're entiled to advocate for smarter writing, but you would be incorrect if you asserted that PhD level writing is suitable for the mass market. I'm not sure that I can think of any examples where that is true and replicatable.
As for your other points, the authors of this infographic had a point of view and shared it. I think you take what you want out of these things and leave what you want. All statistics in Internet-related studies and their resulting infographics are inherently incorrect, and it's incumbent to the reader to determine what's notable and what's not. You seem to have a strong opinion about what's not notable and what's not.
This infographic was good about citing sources, so if you want to understand about any of the statistics that they cite feel welcome to research those.
Thanks for your comment!