Je n'accuse pas

No-one said he wrote plays.

De Vere, in his long and colourful life, made many enemies and was involved in numerous lawsuits. Yet neither any of his friends, nor any of his enemies made any mention of his authorship of any of the plays. What explanation can there be? 

1. That no-one thought it worth mentioning (which begs the question as to why Oxford bothered with any cover-up in the first place).
2. That his enemies, while being quite happy to accuse him of "atheism, catholicism, lying, heresy, disobedience to the crown, treason, murder for hire, sexual perversion and pederasty with his English and Italian servants ('buggering a boy that is his cook and many other boys'), habitual drunkenness, vowing to murder various courtiers and declaring that Elizabeth had a bad singing voice", were too polite to mention his supposedly seditious plays that he had to cover up his involvement with.
3. Courtiers in Elizabethan England must have known Oxford far better than present day Oxfordians. Yet apparently none of them was able to spot the author by means of the supposed autobiographical elements of the plays which have identified him to Oxfordians.
4. That he managed to keep it such a well-kept secret that no-one guessed even many years after his death.
5. That he didn't write them.