One could just as easily say "what has happened to the art of hitting?" Yes, home runs are up. But so are strikeouts. And few players will compensate for defensive shifts by using all parts of the field. I also see many instances of runner on 3rd and no outs and the offense can't score the guy. It is head scratching. But MLB level pitching is outstanding, so it goes both ways. You see guys who were high level prospects and hit AA and AAA pitching when they were younger and then they got a taste of MLB pitching and it is career changing.
As the poster above point out, home run highlights are naturally going to show poor pitch location. Highlights being what they are.
One thing I tend to agree with, however, is the direction of pitching development in general with its focus on elite velocity paired with hard- biting sliders and curveballs. This is swing and miss stuff. Location is obviously important but perhaps not emphasized in high schools and colleges and beyond. It's become a velo world. A swing and miss world in which hitters appear to be willing to accommodate.