The criminals on Criminal Minds are often supremely crazed individuals, people who have little sense and reasoning and just kill people. This is fine for the most part since it allows the writers to let let their imaginations run wild with whatever sick things the unsubs are doing.
"Painless," though, has a case which makes a lot of sense, and we get a good idea where the unsub is coming from, however crazed he may have become. In the aftermath of the school shooting and bombing, it is revealed that those in the "Top 10" lied, telling the press that one of their members, not the unsub, was the one who looked into the bomber's eyes. Already an outcast and then robbed of the attention he could have gotten, he disassembled and became a killer, specifically targeting the 10. Yes, it's still not realistic, but there's more backbone to his motives than in most episodes.
What's interesting to me is the 10--that, after a tragedy like the shooting and bombing, they would blatantly lie to the media in order to promote someone's status. What does it say about their characters? Certainly nothing good.
This episode had a bit more on the side, with Jack in the episode, Morgan pulling a prank on Reid and Reid getting him back, and Prentiss telling Hotch about playing online Scrabble with JJ. Moments like these are rare, especially Morgan's prank in the middle of the case, since it is a bit distasteful to be joking while there's a killer on the loose, but the show is so depressing most of the time that I'll take it.