It's also possible that the idea is not competitive. The article is not quite clear. If it were the case, then it would be irresponsible to continue to finance what amounts to a rather exotic hobby.
I'm assuming "the deepwater scenario" means tethered kites supplying power back to land somehow.
Transmission is always the tricky part, and I'd imagine it is even more so in a deepwater scenario where laying cables is even more expensive.
The system doesn't even need to be anchored.
Keep in mind that the nacelle of a regular windmill is already quite a complex beast, it has one degree of freedom less and can adopt to gusty winds by simply changing its pitch, there is no need to bring the whole contraption back down to the ground before the wind fails to keep it aloft. The only way you can keep the Makani kite aloft if the wind drops rapidly is by controlled descent and that in turn you can do only about as long as your cables are. Typical generators for 'serious' windmills weigh on the order of 30-100 tons, that's roughly the take off weight of a 737-800 on the high end.
Props for actually building it though, that part - even at the limited scale of the prototypes - is quite an achievement.