Joe Mays being called a "solid MLB" is akin to calling Aaron Hernandez a criminal mastermind.
Guy took bad angles, missed tackles, frequently lined up in the wrong position, was a complete and utter liability in coverage (nobody expected a stud coverage guy, but the dude was so bad it was funny) and couldn't organise the D at all. Literally the only thing he could do was hit hard, which while aesthetically pleasing isn't all that relevant in winning games.
He'll get a job somewhere because he's a solid ST player, and he could possibly be a passable backup as a SILB in a 3-4 defense.
But it'll be nigh on impossible for Irving (or anyone) to be worse at MLB than this guy was for us.