"after all "wind" is part of windsurfing."
Sure, the sport is "windsurfing" - but 7 knots of wind IS wind. On the other hand, there's no "surf" on flat water.....so by your measure, Formula in 20 knots on SF Bay is not "windsurfing", but just "windflatwatering"....or maybe "galechoping". In the ocean it'd be "breezeswellering". :-)
It'd be easier to just accept that even 1 knot of wind is "wind", and the "surf" part comes from the fact that we stand on something like a surfboard.
And of course, the "Windsurfer" label came from 12 foot boards designed mainly for light winds. The original board is still a Windsurfer, even if it's sailed in 2 knots and flat water, and in the same way other longboards are still windsurfers.
If you don't want to sail in light winds that's great. Whatever floats your boat (or board). But let's allow for the fact that many people in club racing want to be able to go down to sail at a certain time each week, and in most places that means regularly sailing in light winds. The alternative is that people start not turning up unless it's breezy, and then the fleet can gradually fade away as people get out of the habit.
The other thing is that one way windsurfing can easily get the infrastructure it needs (and get visibility in front of kids) is by becoming a part of an established sailing club, and they tend to dislike having to organise racing for a bunch of people who don't turn up unless there's a planing breeze.