It is not just the newbies either and it is not limited to certain galleries.  There are seasoned artist that never give credit or mentioned to models used, they just soak in the acclaims and wows like it was all theirs. 

Yes, sometimes it bothers me; sometimes it doesn't.  When it doesn't I'm usually in a mindset that the item was given to them as a freebie or they purchased it and the right to use it.  Very fine lines of legalism and just plain courtesy either way.