Sold my bike and gave it up in the mid 90's. For the same reasons as everyone else. Riding in Phoenix, AZ, it was only a matter of "when", never "if" you were going to get creamed. Had many, many close calls. One friend who also gave up riding before me likened it to "You're driving at night, full black bike, full black clothing, and no lights on bike, no street lights". That's the way you have to ride, like you are utterly invisible. Had countless times where someone would look directly "at you", and then pull out anyway. Used to ride with 2 fingers over the brake handle all the time.
Also drove a tow truck, same area, for 3 years. Had to clean up some pretty horrific accident scenes in that time. It sticks with you. The only thing a helmet will do for you is MAYBE your next of kin will have the option of an open casket funeral if you're wearing your helmet. Unless you just miss your footing and topple over when coming to a stop sign that is. May keep you from getting a knot on the side of your head if you bounce it off the pavement. But if a car hits you, at speed, you better try and crawl your whole body up into that helmet before the impact. At highway speeds, you're going to die. Helmet or no helmet.
Or the Wild Hog's wannabees (referencing the movie with Tim Allen, John Travolta, etc), that get all gussied up in their bad-assed wannabee biker outfits, and try to keep from dumping over their full dress Harley's that they clearly can't ride well, with a power to weight ratio that they just aren't capable of handling, so they can play "Biker" a couple times a year, ride to Sturgis, etc, etc. Most can't even negotiate a curve in the road, let alone actually ride along staying in their lane, and God Forbid, keep a steady speed on riding down the highway.
Sometimes I miss riding, when the weather's nice, nice open road, etc. I still have my bike endorsement on my license, but I doubt I'll have another street bike again.