Sonic is designed to be highly recognisable and interacting with Sonic media necessary means you see Sonic a whole lot, even seeing just a few adverts for the franchise is already enough to make you remember it. Shakespeare’s looks are known only on the basis of a couple of portraits, most of which are probably not even based on Shakespeare’s looks directly, and they’re all completely irrelevant for interacting with Shakespeare’s work.
And considering there has been debate for years if Shakespeare was real…