I can't speak for others, but I'm a hot head. I have a quick temper (although it also burns out fast) and I think for me, a weapon is a very bad idea. I could easily see myself over reacting to a situation where I felt threatened and ending up in front of a jury, or hurting myself by mistake.
I agree a weapon is not necessarily a good idea. You need to be prepared to use it without hesitation, which you're probably not, and the person who is attacking you probably is. In which case you will most likely find it turned against you. Best bet is distraction, the light was a good idea, not looking like a target also, an air horn. Or try this, carry a few singles, someone comes you throw them at them and head in the opposite direction. They don't know it only a couple of bucks but they'll likely be distracted long enough for you to get away.