ff is right - airfields need to make money to stay afloat unless they have generous financial backers who don't mind losing money....(if anyone knows of such people, please send them my way...
)
I would have suspected that the QXC would have found out about the non-availability of Sywell when they PPR-ed rather than mid-air...? In which case probably no real hardship.
If you want an "excellent" example of "other events" interfering with aviation, come to North Weald, where, amongst other things:
(i) the regular Saturday/bank holiday market prevents the cross wind runway being available, regardless of the wind direction;
(ii) regular drag racing closes the main runway about 4 times a year, always at the weekend and always in the summer time.
(iii) this year saw events on I think 3 consecutive weekends that closed the main runway one day each weekend in the height of summer, just after the rainy season had passed - drag racing, model flying plus something else.
The price we have to pay for the facility I suppose.