I've been thinking about this for the last couple of years, but there is a real push for these running QBs to take over in the NFL. Probably because that's what high schools, and then colleges, are producing because that's what wins at the lower levels. It's tough for a true passer to really get a shot these days at lower levels unless you're a freak specimen and can run well enough (remember, even the Mannings ran the ball at a serviceable level in high school). But at the NFL level, you have to have a thrower these days, and that's been the case for a long time. In a general sense, if you aren't accurate, you aren't going to make it. And by make it, I mean be considered truly one of the top level QBs in the NFL. If you can also run, that's obviously a plus, especially around in the pocket.
These guys like Nix are runners, man, so I don't get it. There are always extraordinary circumstances like Hurts, who was on a super team, or Jackson, who is the next Vick. But if you try and run your QB all the time, he will get hurt.
I guess maybe with receivers being so much better now they figure the QB doesn't have to be so accurate?