I wrote a little bit about this below (https://news.ycombinator.com/item?id=21337892), but I think that a lot of that perception is because lisps (with the exception of CL) have traditionally been things that people tinker with as a hobby. Once you get a significant number of people making a living working with a language, suddenly a lot of people want barriers to getting their work done removed. And Emacs, for all its benefits, can be a significant barrier to getting work done for a lot of people. Plus there are those of us who just think that life is too short :-)