I'm of two minds about this.
On the one hand I've really gone on a rant when some people *cough* take photos of people inworld to post on a blog and ridicule. To me, just having bad taste or poor slider skills is not enough to be stalked and photoed and ridiculed in public.
On the other hand anyone who is selling something IS putting it on public display, for public assessment, so they will BUY IT.
No one would think, omg, you can't say that CD sucks it would hurt the artist's feelings.
Well, if they were giving it away, maybe not but..... let's be real, all of us have been shocked at something we have seen for sale in
SL that we wouldn't take if they were giving it away.
Personally, if someone posted something I made with a WTF and everyone agreed, I would be hurt but grateful to a certain extent. I really don't want to think I'm fooling myself about what I create. On the other hand if it was selling well I would shrug and post, well it may not be to your taste but my customers like it so too bad for you.