You're absolutely right... none of the Big Boys have the patience it would take to build an all-news station in the market.
However, take a look at the history WINZ had in the format. Now, granted, this was before consolidation and corporate radio's ADHD issues, but I believe they lasted nearly a decade (they picked up Rush first in, what, 94? 95?) as an all-news station. That's the first I recall hearing talk programming on the station, and until that point, I can remember them being all-news since I remember first being able to turn on a radio (darn near since birth). That's a pretty good chunk of time for a format that ultimately failed. Plus, you add in the fact that this is a market in which FM caught on
very early on and that even by the time I was born (1985) AM listenership in the market had
already started eroding quite a bit, and the more apparent it becomes:
someone had to be listening for them to have lasted that long.
Could an FM news station succeed where WINZ failed? I think so. But again, as you say, no one would be willing to try it.
As for who to put on an FM talker, I'm not sure there are any syndicated voices who aren't already taken in the market, so that's all the more excuse to go local

Neil would be great for mornings, but as for who else to round out the bill, I'm not sure who all would be available (and I agree, R&S wouldn't fly).