What exactly would be impossible, for unfortunately I do no knwo what you were reffering to with that comment.
Anywhoo, my humble advice to you, where are your gosh darn references for anything you have said, so dont say it, cause its probably wrong. That is me using your logic and you can (And almost certainly will) choose to ignore that, but rest assured it also does not make your points any more valid.
You appear to have twisted my words. Generally that's a metaphor, in your case it appears to be literal - it's no longer even grammatically correct.
Unfortunately, in order to disagree with my point, you're telling me that not only is there only one group of people who can "hack", they also focus on something as trivial as console online systems. This is quite clearly not true, and does not require external references - but okay, I'll humour you. I'll literally google "hacker groups", and if there is more than one, then my point is logically sound, and yours collapses.
http://en.wikipedia.org/wiki/Category:Hacker_groups - as all wikipedia pages require external references as well as some notability, that should do for proving more than one group exists. Logically, as "hacking", or unauthorised access of a computer system, is not exactly a legal activity, being listed on wikipedia is not high on their list of priorities, nor is having external resources to reference in such an article, so don't let the small number confuse you.
Clearly, if there are multiple groups, they must have different aims, otherwise they'd all be the same group. See where I'm going with this? Whether it's for fame, fortune, or just to watch the world burn, there are people out for everything. Are you telling me that nobody would focus on microsoft, one of the largest software companies in history? Nobody? Even though anybody who could successfully break into their networks would go down in history (That's fame), could get more details than you could through PSN (That's fortune), and could have a good laugh watching a very large network crash down (That's watching the world burn).
There's a hell of a lot more incentive to go after MS than there is Sony. This was not a random attack, this was opportunistic. The fault lies with Sony having an insecure network, and this is not something that "Could have happened to anyone".