Quake surely defies the transition to mobile phones in a way that Doom didn't (but in the same way that, say, Halo would). It's hard to explain, but its hard to imagine playing true Quake on a mobile keypad, and revamping it as a turn-based game à la Doom RPG would feel... well, it would feel more wrong than it did for Doom.
What's more, who would play mobile Quake. Surely the real Quake nuts would scoff at the thought, or have such high expectations that they couldn't help but be disappointed? Meanwhile, less hardcore mobile gamers may well be intimidated by an accurate Quake conversion.