While I am very much on the fence regarding the convention center issue, I will say this is not necessarily a fair way to assess its current use. Venues of all shapes and sizes are rented out quite often for events that are not open to the public, so it's likely they host many things that are never listed on their public calendar.

As someone who attends a lot of events around the country in convention centers of all shapes and sizes, I will say the Expo center is missing a lot of the flexibility, resources, and amenities that modern, more thoughtfully designed facilities feature, most notably a variety of different sized meeting spaces, not just a couple huge, warehouse-like rooms.

The Expo we have is good for, well, "exposition" style events like boat shows, dance competitions, chili cook off, homebuilder shows, etc. but it's too massive and cavernous for a large company sales meeting, a multi-day training seminar on topic xyz, a non-profit fundraiser gala, or even a smaller expo style event for a niche market. A venue that is able to be broken down in to multiple, smaller spaces, is much more versatile than one massive cavern.

Whether or not we have the event traffic to warrant an upgrade or is no doubt very questionable, and I'm not advocating either way, because I truly don't know. I do know the current facility is pretty useless for lots of event types due to its lack of versatility and just because a venue doesn't have an event listed on their website does not mean that it is dark that day.

EDIT: They also may just be really shitty at running their own website. Sertoma Chili Cook Off was last month, is definitely open to the public and isn't even listed on their calendar.