My only real disagreement with your post, and my last word on all of this, is the perception that anyone is being taken advantage of.
If anyone can find me an instance of actual harm here, I'm all ears.
I expect that if GEC thought it was an issue they wouldn't take part and they could ask much more for their product if they wanted to make a barrier to participation.
If the BF forum knife requires a minimum posts and/or join date, then those criteria are set.
If the porch thinks that there needs to be a higher bar, then by all means, set it higher.
Other than that, everyone is playing by the rules that have been set, as far as I know.
The idea that anyone can or should be dissuaded from selling their own property at a later date to whoever they like, whenever they like, is rather, well-- untraditional IMO.
The people being taken advantage of are the volunteers who are taking on the project for NO compensation because of their fondness for this community.