I use both Facebook and the forum. I am a member of lots of forums. As forums go, this one is clunky and difficult to use. The whole having to resize photos to upload them is a prime example of this. If they want to keep the size down, they should process them themselves after they are uploaded. Facebook does this.
Disk storage is cheap; there is no reason why image size should be an issue.
While I much prefer the forum format, the Facebook groups are moderated. Non-Shopsmith related posts are deleted. I like this a lot.
You can buy and sell through these groups as well, and I have done both. I get the idea that Shopsmith doesn't want people selling in the forum, but it just doesn't work. They go elsewhere where the sales are welcome, and the Shopsmith items get sold anyway, and they may lose a forum member or customer because of this.
Once you know how to upload photos of kittens and babies to your feed on Facebook, you don't have to relearn everything to use the Shopsmith group. Like many people, I need to be on Facebook every day for family and business reasons.
I'm not fond of Facebook by any means, but it is reality. However, read posts here and point Shopsmith owners to the forum.