Na, c´mon. For 130€ you can DEMAND a briliant lineup. This years lineup don´t failed at "big" names(just taking a look at the billing and you see that many famous bands play this year).
The lineup simply failed at the mix. Well, for me that is no problem since I listen most power/heavy. But hey, others expected big names in all generes. We can say: "Hey, you payed for something you didn´t know.", but on the other hand it wasn´t far fetched that this anniversary might be awesome at all generes.
In a way I can understand the trolls. But the trolling is annoying(and most times just dumb). I just hope everybody learned the lesson and only buys a ticket if he knows whats comming. I bought my ticket in may(for 130€) - it´s allways possible to get one.
For the future:
Only buy a ticket when you knew and like the lineup and everything is fine.