The fact of the matter is, is that RO2, compared to other fps,' is very difficult to try to "police." VAC and PB will not catch anything except well-known hacks/hooks. Without screenshots, demos, and/or an ACCURATE 1st person spectator mode to supplement those two systems -- the community and server admins really have their hands tied.
Yes, a lot of hacking accusations are misinformed, but please do not think that because you can not detect it and say "oh I've never ever ever ever seen a hacker -- this game is totally secure" that that is true.
There were definitely people chamming and walling their balls off in competition (when it existed), not to mention using other exploits that were not generated by 3rd party hooks/hacks.
Some solace now is that usually the hacking is worse during those times and especially when money is on the line -- and those days have been over for quite a few months.
However the converse of that is that the "dead period" of games is usually the most desired time for malcontents to test hacks in the game -- knowing that there is virtually no one to catch them or even call them out and hence no repercussion or consequence to their actions.
Hacking does not seem to be a "major" problem in this game as it is in others, but please do not think it doesn't happen and is not happening in RO2.