I knew an occasion where 14mm on full frame was not wide enough (I had to use this setup after failing to procure a fisheye lens in time) - when I was shooting inside a telescope dome at the local observatory. A couple more times during the recent (ongoing actually) trip I wished to have something wider than 16mm - on APS-H this time - in the bag, since I left the 14mm at home; now having the more traditional ultrawide shots in mind. So there's always a reason to use an ultra-ultra-wide. 
I wonder what's keeping them from releasing that lens with AF in the first place. It looks like there are two heads of product strategy over at Samyang, each pulling into his/her own direction without regard to the other.
I wonder what's keeping them from releasing that lens with AF in the first place. It looks like there are two heads of product strategy over at Samyang, each pulling into his/her own direction without regard to the other.