There is a good point here. My experience last year at Combe was spoiled by two things.
1. The Paddock was grassy. All very well but in the kind of rain we had we were slipping and sliding all over the damn place.
2. The two chicanes spoil what would otherwise be a great track. The second in particular takes all the rythm out of the track.
I would think those are the reasons why the bigger championships don't want to go there this year.