Stupid question: are you a TicketMaster/LiveNation venue? Are the other places? Bands get forced to sign exclusive contracts if they want to play at any TM venue, and I wouldn't be shocked if they're forbidden from disclosing this and have to make up excuses.
Ah HA! The stark jackboot of consolidation?
Naw. I'm with the commenter who suggested payoffs up front are the cost of doing business, and probably more than worth it in the long run. Honestly, Jamie, for all your weird obsessions with tentacles and people who wear boxes, you're probably up somewhere in the top handful of percentiles in the ethics category. It's part of your fanboy-attracting charm, really, a lot more than those screensavers or the snide comments.
Seriously, have you ever tried to offer an agent anything under the table? Ever?
As much as the thematic / image issue is apparently only a tiny part of it, the fact that someone had to point out that 19th century bicycles are currently Appropriate Decor for the Steampunk-Hipster-Wants-To-Look-Sensitive-To-A-Girl/Actually-Is-Sensitive indie rock demographic says that maybe "I Am Having Trouble Imagining This As An Actual Thing That Could Happen" is a real contributing factor.
And since you can't get hardly anyone to go first and demonstrate that it *can* work, people may indeed be having a gut WTF reaction ["that high school metal club"] aside from whatever mysterious conspiracy aspects can't be probed.
(Says the socialphobe who lives on the far outskirts of / is nonetheless exposed to and absorbent of all the various media crap generated by the NYC hipster scene.)
So... while this completely fails to address the lack of actually being able to book acts, the commenter who said something like "it's all the black and green" may actually have a point. And, bizarrely-coincident to the first commenter, "amber nights" (alluding to all of tube-amp glow, the color generally associated with acoustic guitar, and cheap beer, while also managing to mesh with the 'colors CRTs came in' convention) might be a way to advocate that you're trying to drag in some actual "rock and roll".
Of course this means you might have to grin and bear some fixie acts to get it rolling, but making it look like you're making an effort to create a thematic impedance-match might shave down that "WTF" hump (leaving only all the other roadblocks and door prizes).
[Man, what _is_ it about you that makes you so satisfying to give halfassed/bad advice to? You're like the Howard Stern of crowdsourcing the incompetent.]
What do actual bands say about it?