In order to sell a lot of tickets, and get a lot of people to show up, the event would need to have several big name artists. These artists demand huge guarantees and they aren’t going to work with a grassroots movement like this unless there is cash to back it up. They have management teams that make all of the decisions for them about which shows to consider and even present to the artist. These management teams take a percentage of tickets from every performance.
The community has grown a lot in terms of infrastructure and organization, but it has shrunk in terms of fans, and exciting up-and-coming names. There are many, many undersold events and talented bands playing to empty rooms happening in this city.
This is not to knock any of the talented artists that do live here, and do contribute, but it’s a fact. The big shows are all catering to the demographic you described — the people who do not care, and who just want the social hour and the party. Even the local bands who have these big shows have become insulated from the community due to management and business.
In order to attract sponsors, the organizers would need to present a guaranteed return on investment. The people would have to show them that if they put up the money it will be put to good use, and make them lots of money in return. This can be done by having a big name artist already attached to the event before approaching sponsors. It can also be done by presenting data from past events and statistics about expected turnout, etc.
Speculating about this stuff is fun, but when you get down to the nitty gritty of it, the logistics are a huge hurdle. Of course all the local artists want to be part of it, but what is needed is people who would actually buy the tickets. The simple fact is that most local artists struggle to get even 50 people to show up at a concert and for this to work multiple thousands of people would need to buy tickets and show up.
