Yeah, but the difference is, Glastonbury is now cancelled and, let's face it, was always going to be. Alton is not #cancelled, nor is it taking place months away in the summer. The park opens this Saturday, amid an emerging national pandemic.
I can understand the logic of the National Trust maintaining admission on their wide, open spaces. Alton has plenty of those, sure, but many more queues, rides and other tight, sticky squeezes, including food and drink outlets where they make most their cash. Seems mental to me.
For reference, Alton did open alongside the Foot and Mouth Crisis in 2001, and they slaughtered all of their farm animals in order to be able to do so.