The places at the front are taken on a first come first served basis so if you want one of those then you have to make the effort. (only 5 vehicles in front of me on Saturday) There is no difference between somebody putting up a small tent / windbreak and a family wth numerous chairs to keep a space - do you want to ban chairs next ? A tent offers shelter from the rain (as it did saturday between 8 & 9) and sun + a secure place to put camera gear without having to keep one eye on it all the time.
The reasons given for taking them down were flawed as the wind was blowing away from the runway - plenty of display boards were blown over during the morning yet these were still allowed.
No - I did not use / have access to / a tent / umbrella / chair during the day