Patents are a "damned if you do and damned if you don't" for kite designers. They take huge amounts of time (which I'd rather spend kitemaking), they are horrendously expensive, like more than US$ 50,000 for just a few core countries (plus at least the same again in a defense fund to establish credibility), and, even after considerable investment, won't necessarily be granted or be defensible because of legal vagaries. Sometimes major innovations prove not to be protectable, leaving their deserving inventors languishing forever, unrewarded, while, conversely, patents can be granted for minor (and occasionally even for already well known) details that subsequently block off "best practice" for years-for example the French patent on the use of wingtip "stretchies" to tension the skins on stunt kites.
Patents also cause public relations problems for designers and manufacturers by generating understandable resentment in those who feel excluded from the free development of ideas. I understand this well because this is how I feel about patents that impinge on "my" territory. I wish there was a way to allow one-off, so-called "non-commercial" use of ideas by amateur enthusiasts, without it costing more to administer than having a patent is worth or opening the floodgates of unstoppable large scale commercial copying. Our sport needs the support of these enthusiasts both as customers and for the huge contributions they make by way of myriad suggestions for improvements.
On the other hand, it just isn't worth the considerable investment in time and money that is required to come up with breakthrough designs if copiers can step right in the moment new ideas become public. It's almost a no-win game and I understand completely why most kite manufacturers choose to stay with the safe but less than cutting edge stuff and put their discretionary spending in to image advertising-and often do so by spinning a line about research and development!