No, only the people investing in this are idiots, the ones collecting the money are quite clever.
Its really difficult to imagine that this is cheaper per power output than a conventional generator. the balloon is big, fragile and probably limited lifetime. Subject to weather, ice, lightning, etc. The supports are not at all trivial - picture holding a balloon on a windy day - the wind X tether will tend to push the balloon downwards - this will significantly limit the max wind speed where this can be used. At the same time the tethers need to resist the torque of the turbine - or it needs counter-rotating blades which are less efficient and more complex. You need a large clear area or if the balloon deflates it could land on something doing damage. If multiple balloons are close to each other, a very stiff multi-point support is needed or they will collide if the winds shift. That still doesn't solve the strong wind problem listed above, so the tethers need to have a system to reel in the balloons when bad weather is predicted. The higher wind speed is nice, but its difficult to imagine building one of these that is anywhere near the scale of a large modern windmill.
This is just a dumb idea.
There are very strong winds very high up (30,000'), but the long tethers cause all sorts of problems - and you need a huge clear area around the supports. (imaging dropping 20 kilometers of ultra-strong cable across a city.........(buses, trains etc.....)