IS there someplace here at QB where the rationale for not allowing watermarked photos is explained? I'm just curious.
I guess there are a couple of alternatives.
You could routinely place a placard with your name or logo on your quilt and actually photograph it with the quilt. OR get yourself into every photo of your work -- heh-- that would stop people from wanting to pin my quilts, I think. Someone can crop your sign or your face out if they want, but it does identify your work.
Alternatively, you can choose to post photos on another site, such as Flickr or Photobucket and then link to that site, though I doubt that would be popular, nor would you be as likely to get feedback from QB members.
To answer the OP -- I think it's a compliment when someone pins your work. Doesn't bother me at all.
What does bother me is when someone take a design I created, mails me for a pattern or tutorial (there isn't one, since I did it improvizationally) and then asks lots of detailed questions about construction methods and measurments, etc, only to go and publish all that I gave them -- freely, as their own pattern, which they charge $12 for. That did bother me.