I don't think that robo umps would make a huge impact if we use the existing strike zone as a template. I haven't looked at the data you are discussing, but even if there are ~15 mistakes in a game, it doesn't mean that they are all in favour of pitching. Changing a few missed balls to strikes and a few missed strikes to balls doesn't fundamentally alter the outcome.
What needs to be done in addition to robo umps is an alteration of the strike zone and/or a change to the mound. Then you're giving a real advantage to the batters.
The other thing that we haven't discussed in depth is the shift. I still struggle with the idea of banning it, but I do understand the problem that MLB is trying to solve by doing so.
The shift has led to three outcome baseball by making it less advantageous to put balls in play. That's why we're seeing things like increased launch angles, more strikeouts, and high fastballs. A lot of these problems go away if you ban the shift. I don't know if it's the right move, but how else do you solve the BABIP problem and make the game more exciting?