If you played it right and had a fun variety of stuff, and put it in the right market, I think you could pull off a mead only bar.
I'm in Colorado where the craft market for everything is exploding... beer and spirits especially, but now we're seeing small wineries popping up (there's even a couple that got approved in people's garages). In my county, a winery is now allowed to be placed in a commercial district, next to other stores and restaurants, and not strictly in industrial zones like a brewery or distillery. To me, that sets the stage for a mead bar since customers can pop right in while they're out shopping and/or eating, AND the community at large is all about trying new things and supporting all the craft businesses.
I recently had a wine tasting with people who mostly have never had mead, and they drank up my whole supply in an afternoon, over 5 gallons, leaving me with only two unopened bottles. I had 6 different kinds there ranging from dry oak aged stuff, to bochet to JAOM. Everyone was absolutely amazed at what one can do with honey and a little creativity. These people hadn't tried mead before for similar reasons, "I forgot there even WAS a thing!" or "Where do you even buy this stuff?" The exposure just isn't out there, IMO.
I think if you planned a few events properly to get the word out and overlapped with a few local businesses, like beekeepers and fruit farms, you could do very well, provided you had the product to back it up. I can't speak for all states, but CO is ALL about buying local, supporting beekeepers, and trying all new types of alcohol. It seems to me that you could find a niche like that in most other states as well.