Pearl Jam have a massive, loyal fan base. I suspect the majority of people attending Sziget this year, based on the current line-up, do not fall into that demographic.
I've seen PJ three times in the past 15 years and the vast majority of people at their concerts are men aged between 30 and 60.
I suspect many of them won't be buying tickets to see Octo Octa, Ellen Allien, Venerus and Argy.