I can see many reasons for this:
1. On surfboards it does not make much sense in these winds, as when 30 knots average you are overpowered with a 5 m2, which is the smallest size most got.
2. Water surface is extremely choppy in these winds, so waves are bunk quite often, besides no glassy surfaces - but in some spots and point/pier breaks it can be awesome though, so extremely different.
3. At some point with higher windspeeds, even with sufficiently small kites, you can not surf as freely Down The Line, as the wind kinda dictates your line somewhat.
4. TT jumping will give you loads of height, but no hangtime and you will drop like a rock absolutely no float with small kites, not something many likes...
5. You will very often be out alone when this wind, which makes it even more risky, besides not nearly as fun.
6. Many regions dont even HAVE winds like this, so makes no sense to have gear for these winds. Some thrive by these few but awesome days, others dont and take the other days which are present very often.
7. Depending on location, some got "bad" weather when this windy, meaning raining/overcast/gusty, which is a turnoff too.
8. The "Being hardcore and out in extreme conditions" feel and status we all have had in the early days of wind and kitesurfing, wears off over the years, and many seek the best cleaner conditions instead.
Having said that, it can still be awesome, and many aim for this
Peter
