Here's the problem. Beyond a certain scale, you need lots of money to run these things. Like many millions of dollars. And you're not getting that much from plebs or Bitcoin-only companies, so they have to bring in the people that are willing to pay, like altcoiners, bankers, governments and other scammers. And they want to see politicians and other people that they get along with. In other words, beyond a certain size, these events are funded by fiat money.

True Bitcoin-only conferences rarely scale this much.