A lot of successful products are copies of something else, and more power to them. The company I work for* had a competitor make an "embarrassing copy" of our flagship product, and they managed to get acquired because of it. But you know what? I don't hold it against them, in fact, congrats to them. If anything it validates the space we're in.
* I'm deliberately not mentioning the company or product by name, because I don't particularly want to start a subthread about this situation - the particulars would detract from the point I'm making.