I didn't even know Tooth & Nail was a Christian label for the longest time. MxPx and mewithoutyou never really sound like they're preaching at you. But, I haven't listened to anything MxPx has released in the past 5+ years so I can't speak for any of that stuff.
Anyway, since everybody keeps bringing up banRAB like The Beatles and Led Zeppelin, you have to realize people probably make the same argument every generation. In the 80's, a lot of music was crap, but it's been 30 years and people are still talking about The Cure, Echo and the Bunnymen, and tons of punk banRAB from the time. Give it a few years and everything will be different.