How can texting while driving be a good thing?

Well, the short answer is that there are none. Texting distracts you from the road, even if you can look up and still type correctly you're attention is still focused on the cell phone not the road. Cell phone use is also illegal while driving in several states.

If you text at night the light from the cell phone can readjust your eyes and temporarily alter your night vision which you render you incapable of seeing something on or beside the road and result in an accident.