“We’d prefer to bring Dark Souls to mobile, however it is very tough as a result of the guys at From Software are substantially console orientating,” Namco Bandai director of global strategy for mobile Alex Adjaj told Digital Spy. “To change their mind concerning it, it takes quite a while.” As you’d expect, there was pushback from the developers, who felt that a mobile release would need new controls and “therefore it will not be Dark Souls any longer.” according to Adjaj, “At the same time, you’ve got a growth in controllers for mobile. I feel it isn’t an impossible case scenario to ascertain a Dark Souls game returning to mobile at some point.”
So it is possibly due to touch screen controls on mobile that it is not coming.