Maybe I misunderstand this, but I doubt that this matter can be generalized like this. I think, doing something that someone else enjoys is most certainly part of "their own pleasure and enjoyment". Otherwise there would be no real point in releasing something free to the public.
I also think that criticism and being thankful can go along together. If someone is pointing something out politely and with the goal of improvement, as a developer I would be glad to hear this. At last, it could be something important that I have missed myself and feel that this should be corrected. It just all depends on how this is done. I'm glad I see this here at SOH being done that way (mostly), very professional.
my 2 ct.
Cheers,
Mark