Lots of talk about this in Dutch media. To clarify:
Verknipt was a semi-outdoor 2-day festival, multiple big sweaty tents with no ventilation and smoke machines. It was a rainy weekend and people took shelter in those tents. Also, lots of people went into so-called party busses before and after the festival. No one knows if people actually got infected ON the festival terrain, it looks more likely they got infected before that. Testing for Entry went wrong, Dutch government could learn from that for the remainder of the festival season and shorten the time between the test and the entry to 24 hours (it was 40...).
Also, our hospitals are empty. 5% infections on young people who are not getting sick from this virus is actually a good thing. Let the young build up herd immunity while the elderly are vaccinated and protected.
I agree with you that the media makes this a big thing and that this is threatening the festivals in The Netherlands for the coming weeks...but that would be a wrong and fear-driven decision. However I fear this is indeed the (unjust) death blow for big multiple day festivals like Lowlands, MysteryLand, DGTL, IntoTheWoods. I'm currently switching plans to smaller scale events in august/september...