Why? It's quite convenient for my left-hand pinky on nearly every keyboard that I use, and I've picked up the habit of doing periodic `jk` movements as I'm examining some code. I tried the `jk` combination that some people recommend, but it doesn't work for me.
I've never used a keyboard where escape was convenient to press. I personally use inoremap so 'jk' only does something in insert mode, I hit jk repeatedly all the time in normal mode while I'm thinking.