In the last ten years, farmers' markets have boomed. Got more public demand? Add more booths and start up another location. Farmers' markets are scalable.
I think there are number of areas where handspinning is faced with scalability issues that have potential to hold back its spread. One is the limits of handspinning guilds.
I find guild meetings are vital living banks of support and information for fostering handspinning. I tell anyone who is even remotely interested that they should come visit a guild meeting. At the one I belong to, interested members will give beginners a little assistance to get them started. Members do this on a volunteer basis as needed during regular meeting time. I've done it, just as other did so for me. When you volunteer, you give that time at the expense of your own handspinning and your own conversations with experienced spinners. As a result, there's a prospect of volunteer burnout. Our guild refers beginners to community parks and recreation programs, folk schools, and local yarn shops where they can sign up and pay to take handspinning lessons. The guild also runs programs and hosts workshops during meetings, giving all members the benefit of the presenter's expertise.
It is common practice for handspinning guilds to be open to all new members. Yet, guilds have practical limits for their ability to seat everyone at their location. You can't just all get together and spin under a spreading tree. I mean, you can, but you wouldn't call that a guild. Think of what would happen to any volunteer organization that has to deal with an influx of new members, whether the newcomers know what they're doing or not. Wonderful problem to have, yes, but certainly a scalability issue. Handspinning guilds are non-profits that operate according to membership policies mandated in their by laws. They would require time to adapt and address scalability problems.
One solution would be to establish a new guild nearby and hope the numbers naturally sort themselves out. When you start a new farmers' market, you usually create a new paying job for a market manager. Your market partners with municipalities or regional districts, businesses, and community groups to get land, supplies, training, publicity, and community involvement. As far as I can tell, fiber arts guilds are much more on their own. When spinning off a new guild, there's a risk of shattering social capital, diluting drawing power (a large, established guild can more easily book experts for workshops), and inequitably allocating resources (library, equipment, capital).
I don't know of any guild facing a sudden, significant population boom. On one hand, I'd kind of like them to, but on the other hand, the consequences would definitely be unsettling for a while.