"Statements such as "there is no difference between the official and the fringe events, they are all part of people enjoying themselves" are quite insulting to the people who give up most of their leisure time to organising the official events."

This is not insulting in the least, it does not discuss who does what to achieve the festival, it simply states that the individual draws no distinction between the two and enjoys it all as one big package.
And that from the horses mouth.

Mentioned above means mentioned above, its not meaningless because it means mentioned above, as in above.