I am not arguing that this is not possible with clone stamp, just that a "smart" tool makes it much easier and more convenient.
While it is possible to paint a house with an artist's brush, and I have no doubts that some people can even do a better job with it than I can with more suitable tools, it doesn't mean that it is the best tool for the job. It currently takes me more time and effort to achieve inferior results using the existing tools in paint.net, and I am sure that I am not the only one that will benefit from that functionality.
There other other threads in which plugin authors are lauded for providing better, simpler, faster or more convenient ways to achieve results that were possible before. Why is this different?