If the case, then it's evolution into easiness, which is often a main reason put forth by kiters for the switch. I have not a problem with that argument.
Overall windsurfing - of all flavours (formula, speed, waves, freestyle, even just back-fro in strong wind, and even more learning, which takes time and is exhausting) is waaayyy more of a sport. After all sooner of later you have to unhook, work with the upper body, etc.
Yes you'll find counter-examples - i.e. a 2m sail in a 2 knot wind, but you're really scratching the bottom of the barrel with this example.
Anyhow, again I have no problem with the argument that it's an alternative (not really an evolution, but we're playing with words) into something easier to do. Not at all. I myself teach windsurfing to selected newbies every summer, and I only pick those really interested in working hard. For those who want something easy, effortless, quick to learn, I'm the first one to point them to other activities.