How long is too long?

I was at the Mt. Gretna Outdoor Art Show in Mt. Gretna, PA this weekend- it was a hot, sunny day, perfect for walking through a wooded area filled with booths of all kinds of artwork. I went to this show for the first time last summer and I remember being pleasantly surprised by a lot of the pieces I saw. So many times at various art shows, I feel as though I'm seeing the same paintings, the same photographs, the same ceramics over and over and over again. At the Mt. Gretna show, I felt like I was seeing innovative designs, mediums and subjects. You can imagine my excitement when I realized I was able to attend the show again this year. Once again, there was a decent variety of artwork to see, so it was definitely an enjoyable afternoon. There was one artist from whom I bought a print last year. It was artwork that really made me smile, and even laugh. I had a strong reaction to it and absolutely HAD to have one of his prints. There was a whimsical quality to his pieces that really spoke to me and I thoroughly enjoyed looking at each painting. He had a booth at the show again this year, so of course I looked through all his pieces again. I was disappointed to see not a single new piece. I understand that his particular style of painting is very time consuming, but at the same time I felt that after an entire year, he should have had at least one or two new pieces. It got me thinking about fashion designers as artists- they are expected to produces dozens of pieces each season- at the very least twice a year. If they don't, as Heidi Klum would say, they're "out." There certainly must be a tremendous amount of pressure and I'm sure that as a designer, you have to find the happy medium that works for you- producing enough new work to remain buzz-worthy while at the same time maintaining the integrity of your work. So am I being too hard on this painter from the art show? I was really looking forward to seeing some new works from him and it was ultimately disappointing to see that he had nothing new. I suppose that just because there was nothing new at the art show, that doesn't mean he didn't produce any new works this year, so maybe I am being too critical. After all, as an artist, you try to keep your fans happy, but they are not the reason for your work, but how long is too long to produce something new?