Students emulating their masters is a long and honored tradition. In the Middle Ages, students or apprentices, would work in a guild under the knowledgable eye of the master, gaining skill and experience with their craft. It took many years to become a master and not until the apprentice could recreate the master's work perfectly, would they be allowed to move into that honored role. So we now have works "from the school of..." in museums. Remember in the Middle Ages, artisans were mostly anonymous. There were no big artist egos...yet.
Fast forward to the Renaissance and the Artist with a capital "A" is born. Michelangelo, Leonardo, Caravaggio - we refer to them with one name - like rock stars. And indeed, they were the rock stars of their time. Stories even refer to Leonardo wearing purple tights. Sounds like Mick Jagger to me.
At any rate, I'm still wondering why the above-mentioned printmaker was so upset. As a teacher for many, many years I've seen lots of students copy my work. Some of them have even become fairly successful at selling work that resembles mine from a particular period in my career. I can pick up just about any big glossy art magazine, turn to a given page on a "famous" artist, and find a painting that resembles something one of my students has done. In fact, I recently gave a "blind test" to my advanced painting students. I put two paintings side by side and asked which one was the million dollar painting and which was the one selling online for four hundred bucks. About half of the class got it wrong. They simply couldn't tell the difference between an art superstar and a regular working artist.
I love teaching. I love interacting with the students and watching them grow. I love how it impacts my own work - keeps me on my toes technically. I love it when my students are successful and have shows and send me flowers to thank me for helping them. It brings tears to my eyes when I see the light go on for a new student. That aha! moment when they really get it.
So what's the moral of this story? I'm not sure. But maybe, just maybe, if you are a teacher and you don't want people to copy your work then perhaps you shouldn't teach them how to do it.