The key thing about groups like Derptrolling and the Lizard Squad is that by pointing them out and saying "they're the problem, not us" is that it gives them an even larger audience, more attention and therefore makes the said company a better target (because the DDoS'ing idiots get more attention from them).
Ideally, groups like this get no attention and smolder until they realize they're not going anywhere, but because of the nature of the internet and the vulnerability of general internet services to something as simple to execute as a DDoS attack (after some recent jumps in their side of the arms race) groups like this are getting quick celebrity status.
tl;dr They're not being bad about it, they're being smart about it.