There are many types on concerts. Personally, I use to enjoy the more flashy concerts, but as I matured I came to enjoy the reach and emotional dveykus over the flash.
That said, there are concerts that are basically giant tishim. Eitan and Shlomo Katz for example, give very deep concerts. Full of Torah, full of Dveykus.
If anyone has ever been to the Yud Tes Kislev concerts in Yerushalayim, the flash serves the ruchniyus. The lighting and video effects are flashy, but showing divray Torah and insight into the music. There are divray Torah leading into just about every song, giving newer, deeper insight. And there is big fabrengens for a couple of hours before the concerts, as well as a museum of chassidus to put you into the mood.
There are ways to do concerts, even with flashy “rock and roll” that are spiritually uplifting. I have tremendous respect for Rav Miller, and in this instance there are other points if view from big rabbanim as well.