It's the timing. I too think he'll be a good face, but he's a great heel too, and we've only seen like 10% of what he can do with that role. I'm baffled that people want him to turn face the minute he gets more TV time. Let him be a heel for a bit, and then turn him. And whether you have the tools or not, you can be a bad face. Cena is a shit face and we all hate his character, but most agree that he has the tools to be one of the best in WWE. WWE could easily book Ziggler to be the boring superface, or a face character like Miz. Punk was even stale as a face, and he's the best talker in wrestling (in my opinion), so WWE can easily fuck things up.
Why would anyone be begging for this right now? Let it happen a couple or even many more months into his reign. If he's a good enough performer, he could get boos. His gimmick doesn't suck like ADR, and ADR simply could not get boos. We saw Ziggler/Foley where Ziggler got a lot of boos, so he's easily capable. I don't think the ADR/Ziggler comparison is a good one tbh.