At this forum, we enjoy making planes to fly with, and help others make something to fly with. Some more or less wants to also make it "natural" best possible, others not. Anyway we all enjoy the community if is about FT planes, or forum members own designs.
What FT, then of course also John if are under cocoperaton/contract with FT, have at goal, are of course as a company to make models/plans on planes that sell! Thats standard commercial way "of life"!
Of course, if main of members here talks, wants, make, a "Birdie-plane" over time,.... John or/and FT see this as commercial interesting to have such one in their line. Stealing, copying? If are exactly a copy of a members shared plans/build method, the member should be credited as least though. But if you make a Birdie, and John/FT make a Birdie with some changes on how did it, its not any such.
The idea isnt something we could blame others do, planes in all different shapes are done over a lot of years. Even just Aerofred have approx 11000 build plans , if someone makes one similar, or after the planes, then we could say we stole it too...or?
Most of in scratchbuilding do something the way we want, to fit better, or we believe thats a better way of doing it. Whatever if its 100% similar in view... it doesnt need be in how made.
We need see the difference of a commercial actor, and a private hobbyperson doing just for fun. As long something is shared, it will always be others closing up to similar idea. And to "complain" on a commercial actor because made something similar as you done... is a jealousy on reputation, or money of others, instead of enjoy your self by the satisfaction that youve given such, by a idea other would use.
A moral aspect isnt a virtue all over mainly, remember that! If someone is afraid someone copy your work, then you cant share it!