My two bits.
1. Fear factor:. Worry about am I capable to build this. People at my sailing club are very surprised at how light the kayak is. And we do have people who build their own boats there. But sailing is also having it's challenges in attracting new people, and this has been going on for a few decades.
2. Space: Today's new houses are very cramped for space, both house and garage. I can build a 17 foot kayak but it would be very cramped. The Ravenswood is about as big as I would want to get.
3. Material: I was able to order the cedar strips, so basically I wound up with a complete kit that only needed some scarfs glued. Even then I am lucky to have a very long hallway coming in off the front door.
4. Independence: I am perfectly happy to do something myself that is new. I will research the bejezers out of something, which is why I purchased the kit from Kudzu instead of going with stitch and glue (Canadian winters do not agree with epoxy and I don't have a heated workspace) and I am not OCD enough to do cedar strip. And I know that I make mistakes the first time and will work through them. Every time I look at woodworking or boat building classes they are always sold out. There is a lot of comfort in having an instructor available to answer questions and provide guidance.
5. Attention span: Don't really agree with this one. I have been a cub/scout leader and they do have the ability to do so. However a 2 hour meeting once a week would not make a kayak. Don't have the space to store the in transition kayak. If I can get an 11 year old to cut, lash, and stitch over a one month period to make a kayak most kids should be able to do so. What might be lacking is the adult who is willing and able to put the time in.
Possible target audience: Junior high and high school construction classes. Here in Canada that would be Grade 7 through 12. Several classes a week, have the space and the tools.