I see nothing wrong with wanting to be thanked for your work so keep up the good work you do. I do take a lot of pictures because I enjoy walking cemeteries but it's very rare that I actually fill a request so most of the time I don't think anyone notices when I put up a photo on a memorial. My enjoyment comes from helping make the memorial more complete but if a thank you or two were to come my way they would be appreciated!! Oh and when I say I take a lot of photo's I think I've posted about 2,000 which is a small number when compared to many others!
By the way I had not read the entire thread, I was simply sharing what I thought was an unusual email I had received from a fellow find a graver.
I have just been reading the comments on FAG Addicts about your not being thanked and I totally agree with you. I didn't want to get involved in a back and forth argument on that group but I think you are right. I do not take photos of gravestones and such but I do help out others with their genealogical problems and queries. I have had some bad experiences but a lot of good ones in which people take the time to use those two simple words, "Thank You" and it means a lot to me. It's just old-fashioned courtesy to thank others for anything they do for us no matter what it is. There's nothing worse than people who get information or photos from you and you never hear from them again. It shows a lack of respect for you and your work.
Anyway, that's my two cents worth. Keep up the good work and I thank you for bring up the topic!