The clincher for me is that many of Shakespeare's contemporaries, close friends, and coworkers, including Ben Jonson, didn't say a peep about any ghostwriting and indeed stated repeatedly that Shakespeare was the author. The preface to the Folio, correspondence, and published works acknowledged his authorship. Contemporary evidence is to be favored over "cipher" analysis, speculation, and theories about motive 400 years after the fact. A conspiracy that involved all of Shakespeare's writer friends and his publishers seems highly unlikely.
I think most of the original objection arose because people thought that Shakespeare, "merely" a middle class, hardworking man and a player, could not have had the education to write about his subjects. People today don't realize just how good a typical 16th c. education was and how well-read anybody in literate circles in England had to be.
I so agree with you, especially the part about education. With “universal literecy” today, we are so much LESS educated than the few were were at all educated back then. The children of the Tudor royal family were reading and writing in four languages before they were ten. Shakespeare attended a grammar school where he learned Latin and the calssics from an early age. Getting to sixth grade then was to be more educated, culturally, than a college graduate today.