It isn't unfair really, this chaos happens on a smaller scale every year, this year it was just amplified by the weather. My other gripe is the horrendous G4S staff (who you've probably heard about this week) who aren't worth the air they breathe.
I've been twice in the last 3 years and haven't had any bother getting in or out or moving around the site. In fact Silverstone has been very well organised for a long time now, especially since the A43 was made dual carriageway all the way there from the M1 and M40 (which they largely paid for), and all lanes head to the track in the morning and away in the afternoon. Very well organised for such a large event.
The only issue I had was last year when the queuing for the park and ride at the end of the race was a bit chaotic but they're working on it. Apart from that I have no complaints.
I've seen them just use two lanes on the A43 all the time except after the race when they used all four. I agree when they get their act together they can do a good job, but they simply don't manage to do it consistently.