Plummet is far from average. I think you sum up the problem with switch right there. They get their information from their pro riders, which ride a limited aspect of the sport. There are pros out there trying new stuff but the gear is only now starting to catch up. Ignoring the fact certain foils have been good at this stuff for a long while now.
"When there is enough wind, say over 10 knots, any (modern) kite is not too heavy. Then lift is so much bigger than say 100g "overweight"/m2."
This statement exposes so much lack of experience in riding it's leaves me almost speechless. How many kites can handle well being pushed faster than 10knots at the kite in 10knots wind or even less. Not many. Infact not many kites can handle being pushed 10knots at the kite in 20knots wind.
Good L/D ratio is awesome but far from everything a kite needs for everyone.
Lack of inertia and quick turning are not as important for some people. These some people would include some of the best riders in the world who complain kites turn too fast. Average riders like fast turning kites because it makes them feel great they can pull off kiteloops and other stuff easily.
The helium has better weight compromises for light wind, but it is still not as light as other kites out there. It also only comes in larger sizes. What of people that aren't fat blobs or like to ride bigger boards.
Switch seem very on demand how hard could it be to offer custom fabric choice or a strutless kite. Not everyone gives a crap about lifetime guarantees. Reality checked for experienced riders ,everything breaks.
Board riding maui seems the only brand that has cottoned onto the fact, the pursuit of a lighter and maybe more flexible kite, even with it's compromises, is well worth it. Brands like flysurfer have been pursuing it for awhile without actually understanding the full benefits of what they are doing.