I appreciate the main points here: that the faith formation of young people begins in the home (see this Century interview with another Lutheran) and that the main thing that draws anyone to the church is not pop-culture sensibilities but the proclamation of good news (an even Lutheraner notion). But I'm not sure what this has to do with the U2charist and the other single-secular-artist-themed worship services it's spawned.
The video implies that the (misguided) goal of such things is to get young-adult bums in the pews. And I'm sure there are those who think of it that way. But I haven't met any of them. Sarah Dylan Breuer, who created the U2charist, certainly isn't among them:
The U2charist is a demonstration of one way that liturgy can bring people together to celebrate what God is doing in the world to bring justice for the poor and reconciliation for the world. It is by no means the only way to do so, or even necessarily the best way for your congregation. If your congregation doesn't really know or like U2, it may feel forced and awkward to use their music without substantial adaptation in liturgy -- and if it feels forced and awkward for you, that's probably going to come across to anyone who does visit your church for the first time for a U2charist. That probably wouldn't be the best sort of circumstances in which to try such a service; there's little that's cool or fun about a bunch of people doing something that they think is no fun at all because they think it would look cool to others.
The people I know who have planned and executed U2charists, etc. aren't thinking primarily about outreach-to-the-kidz either. Neither are the people I work with in my side job as a church musician, where we do several such events each year.
Now, this is a church where youngish adults are already overrepresented, and where the musical culture is nontraditional and eclectic. This is key: the pop-star-themed services are organically related to what we do every week, not some gimmicky departure from it. The morning service makes enthusiastic use of a wide mix of pop music. A U2charist makes sense there, and they've done several. The evening service—the one I help lead—is more invested in folk, roots, and country-rock music. A Dylan-themed service (Bob, not Breuer) makes more sense in our context, and I've planned and led a couple. We've also talked about doing a Johnny Cash-themed service sometime.
Attendance always goes up for these services. But that isn't really the point. The point is to proclaim the gospel from a new angle, to engage in a fresh way—by taking something that is already part of what we do and giving it a one-week special focus, as other churches do with any number of things. In a context where popular music styles are the norm, and where we decline to observe a strict separation between the sacred and secular when choosing source material, this is a very natural thing.
Not that I'm entirely gung-ho here. I do worry that U2charists, Dylancharists, and what-have-you-charists can make it far too easy for the music to eclipse (rather than support) word and table and assembly. And it can be tempting to choose songs with only inch-deep connections to the role they're being asked to play in the liturgy, or to favor comic juxtaposition over something more deeply generative. (Probably better not to close a Dylan service with "Most Likely You'll Go Your Way and I'll Go Mine, to Love and to Serve.")
But the fact that such pitfalls exist doesn't make them unavoidable. And the fact that churches have special services that some younger people are drawn to doesn't mean the service exists simply to be youngster bait.
(As for the Gilbert & Sullivan Mass, I actually see some exciting new ground there—if what we're talking about is a music-driven liturgy with upbeat, singable, call-and-response songs. If it's merely Sullivan-penned strophic tunes you want, the Episcopal hymnal's already got you covered.)