Javon Kinlaw: boom or bust

South Carolina defensive tackle Javon Kinlaw is the newest 49er.When Matt Millen was president of the Detroit Lions in the 2000s, he displayed a habit of drafting wide receivers in the first round. Same position, year after year. It got him fired.

The 49ers have become the Lions of the new era. Their position is defensive line, and they can’t get enough of them in the first round. Arik Armstead. DeForest Buckner. Solomon Thomas. Nick Bosa. And now Javon Kinlaw, all in a six-year period.

So why are so many 49ers fans feeling giddy about Thursday’s pick? Because the Niners had a hole in the middle of the D-line after trading Buckner to the Colts. Because as they showed last year, a disruptive…