I'm an employee of the Avalon Airshow and like many other employees and volunteers have been working very hard to produce a good air show, all the time coming up against budgetary constraints, like everyone else, including exhibitors both civilian and military. It is good to see that the majority of people understand this and enjoyed the show we have produced.
Unfortunately exhibitors can't be forced to stay for the public days, they are there to sell and when the selling is over they leave, cutting down on hotel costs, transport costs etc. so that their employees can be gainfully employed elsewhere. Serious buyers will probably have contacted the exhibitor of their interest first, may even have got their trade day invites from them, the hard facts are that very few, if any, of the public day viewers are serious buyers. As has been mentioned, the professional salesman knows instinctively who the serious buyers are, regardless of clothes or demeanour.
So they don't care about public who pay for the show and also support the show???