I was just watching CSI and commented on that myself!
I guess the technical answer is that it gives the show more atmosphere. At the very least, it's nowhere near as dark as the X-Files used to be. And Mulder and Scully had some crappy flashlights back in the day, too!
I just saw an episode where there were bomb threats all over Vegas. Eventually, they caught the bomber, but at the end, someone found a bomb in a school, and for some reason, rather than say a bomb squad, the CSI crew showed up!!!! What on earth are they going to do to defuse a bomb? It's not always logical, but it is a good show, I especially liked the one Tarantino did last season, very tense.
Although, I gotta say, this show must make real CSIs jealous that their jobs aren't really like that. These guys on the show are out there setting off bombs to calibrate shrapnel impact, having gunfights, etc. You know 90% of a CSI's job consists of running numbers through computers or walking around a crime scene for hours looking for one hair or drop of blood or something. Must be boring work.
