Probabaly those who can afford grand stand are those who could afford to buy photos that were taken by official photographers. SO they would rather enjoy with two eyes watching the event. Also to avoid blocking view of others who paid $$ for grand stand seats.
If it's really that class of ticket, I'd say it's better that way. You'll be rubbing shoulders with the rich and famous, do you want to be mistaken as the hired photographer from Peak magazine? It would really make you look unglam if people are holding champagne flutes and you're holding a 300/2.8.
And I think the others would appreciate being able to view the action without being distracted by your dslr motor drive or being blocked by your long lens.
Look- it's an event to be enjoyed, prob with wining and dining. So enjoy!
Thanks guys for your feedback, since the ticket is free. just need to shake a few hands in appreciation haha. Anyway, i'm not really into rubbing shoulders with rich guys. Will just bring in my dslr and see how it goes with a monopod perhaps, at most someone will ask me to keep it. To me probably, its more exciting to take photos of the event then to buy photos taken by official photographers but just my view as i want to be part of it to be able to take photos at a F1 race. ;p