Maybe so. But as "ATC Watcher" already wrote, there is a lot more to these trade shows than just big business. If you want to build (with lots of public subsidies everywhere in the world) and operate flying machines, the most important thing is the tax- and ticket-paying public that you need to get behind you. And all the young people that you need to design, build and fly those aeroplanes in the decades to come.
I was introduced to aviaton by airshows and I got valuable inputs for my career from visits to Le Bourget as an university student in aerospace engineering. These trips to Paris were organised by the faculty of my university becaue they too knew well, how much motivation the future generation of engineers would draw from it.
So "big business", who cares? You can't sell aircraft that no one is designing for you.