Not so, do a key word search for "helmet" here, you get quite a few hits. You can even checkout a post, 4 1/2 years old at this point from Miami at:
Helmet use is just another choice. Some guys do and some guys don't. It is a function of injury and perception of risk aided by industry example and contest regulations, if any. Look at the adoption of helmets in many other activities you'll see parallels.
Some riders might still be here today if they had helmets on while kiting, not all but certainly some. Some guys are still here today or suffered lesser injury because of helmets in kiting.
Things to consider in looking for a kitesurfing helmet:
1. Good, snug and comfortable fit.
2. Close fit and close contour resulting in low drag without avoidable projections (e.g. fixed visors/bills).
3. Light weight.
4. Well padded with suitable material for impact absorption without creating excessive bulk and drag.
5. Good drainage/fit characteristics to reduce water retention
and bucketing potential.
6. A good hard shell for impact dispersal and penetration resistance. Kevlar/high strength composites may offer better penetration resistance than ABS plastic.
7. Strong, corrosion resistant fastenings in an effective retention system.
Some helmets to evaluate for kiting appear on page five of: