There are at least a couple of peculiar assertions in that opening paragraph. One is that The Daily Show uses Christians and/or their belief system as a comedic punching bag. I watch the show pretty regularly, and I really can't think offhand of anything that fits that description. Poking fun at "intelligent design" advocates, creationist museums, goofballs who peddle quack science in an effort to circumvent evidence that conflicts with their dogma, sure. But those people are few and far between as comic fodder on TDS, and when they are the political subtext can be clearly seen. They are not being picked on because they're Christians, but because they're charlatans.
The other notion is that Christians need their own subculture that caters to them. This smells more like marketing than anything else, the business instinct to niche-peddle to people, rather than simply producing something that can reach out beyond the bounds of the niche and have some mass appeal. Bands such as U2 and King's X are probably no less Christian than, say, Stryper was, but they made more of an impact because they concentrated on making better music, and let that universalize their appeal.
Certainly it's understandable why people from socially conservative belief systems might want to actively dissociate themselves from the lame-brained vulgarities of popular culture. But those are pretty easy to sidestep -- I mean, no one's making anybody watch Tila Tequila or any of the interchangeable has-been fuckfests on the E! Channel. No one makes teenage girls wear the coin slot thong, or get a butt hat, or a nipple/clit piercing. People are either conformist mallrats, all expressing their individuality in eerily similar patterns, or they aren't.
Even TDS itself is only irreverent in comparison to the dutiful, slavish handjobbery that comprises most "news" media, particularly television. Stewart pokes fun at Bush's manifold incompetencies, and then has McCain on for the thirteenth time, for a round of softballs that would make Larry King blush. TDS is more of an outlet of catharsis at this point than anything truly significant, a place where we can go to snicker at the abusive absurdities that comprise our political system, and then go right back to either pretending that we can have any effect on it, or ignoring it all in favor of some cheap video soma. That's something that the religious and the secular alike can appreciate.