Good Question!!
I have no idea why they do?
I remember a couple years ago the front row guys would start the race, run a lap and park it. SO i think it is required but I have no idea why?
I agree with N2racin88 that the teams that are on the front row race only for sponorship exposure. The cars are starting up front so most likely they will be up front where most of the TV coverage is at for most of the race. Another reason I can see the drivers on the front row race in the Twin 125s is so they can get a win at Daytona. Many drivers would kill to win at any race at Daytona just because it is Daytona.