That is because if you are not prolifent enough with the linux command like you are more likely to break your Kindle.
I used these instructions from post 118 and 120 (119 is my post) to get SSH over WIFI working:
https://www.mobileread.com/forums/showthread.php?t=97745
But some of these instructions I had to alter a bit to get it working or to understand it (see post 119).