I'm with you on this. I have no problem with a system that gives umpires the correct information, as long as that information is then presented to the players and fans through the umpire, much like instant replay.
I just hate the idea of replacing the ball/strike calls with a computer, or any other change that gradually phases out human interaction. If you replace the HP ump with a camera-computer, why not replace the base umpires with them as well? Install wireless sensors in the bases and gloves to determine safe/out calls. Replace managers with a computer that cycles through data two or three million times faster than a human, and let it make pitching changes and baserunning decisions. Replace the first and third base coaches too. Eventually, we won't need players at all! Or stadiums, for that matter. We can just have each player's career stats plugged into a central database (or in the case of new players, allow them to play 20 or 30 games against each other to establish a baseline and plug that in). Then we can let the computer extrapolate from that data and give us the "results" of all 162 games for each team and the results from the playoffs. The entire season could be scaled down to the click of a button and ten minutes of processing. Then we could have an Amazon delivery drone drop off the World Series Trophy to...wherever. Probably still not the Cubs.
I realize that this is more than slightly hyperbolic, but my point remains that turning any sport into one that is so heavily dependent on computers and cameras turns it from a cherished and personal tradition for millions into an assembly line, churning out "games" for the entertainment of a mindless public. Giving gear to the umps to help them be a little better at their jobs keeps baseball relevant without losing what baseball is fundamentally about: people. Getting rid of the homeplate umpire and letting the batter and catcher stand in front of a machine turns it into an antiseptic bore.