Some of us wish they'd get out of the magazine and trade show business and get back to the professional organization thing.
But the trade show business funds the professional organization. While I actually think ASIS would be a cleaner, more focused organization without the trade show, the money is significant.
From their 2015 tax returns, total revenue is ~$29 million, ~$6 million from membership fees, ~$3 million for training and certification, most everything else from the show and publishing.
Related, this is why IPVM has been firm about never doing advertising / marketing / promotions (like ASIS does). The money is so big that it warps an organization's priorities and decisions.