So much crap spoken about (anti)cheats. You almost make is sound like you know what you are talking about.
As is typical, that information is completely backwards. You post about PB like it is some "firewall" against cheats, and that it has been left weak/vulnerable to attack, and that all PB have to do is make it impervious like some kind of NAT gateway.
Punkbuster is not some kind of "firewall" against cheating. There is only so much *any* kind of anti-cheat (and anti-virus, as they are essentially the same thing) can do. They cannot, will not, and never have been able to just "block" hacks. You do not "block" hacks, because hacks, by their very nature, cannot be "blocked".
Multi-player game cheats work by manipulating memory in real time, and some by manipulating hardware drivers (mouse and video, for example). These changes to memory are usually undetectable to the game and/or any anti-cheat that is running. Nothing can prevent them without blocking everything, including the game itself. The only viable way for anti-cheats to work is the in-process CRC checks, and heuristic pattern checks, against a known list of patterns for cheats. No, these patters are not "can see through walls" they are patterns in binary code.
Anti-cheats are very, very difficult to operate. Forever be playing "catch up" with the ever expanding list of available cheats. With a game as popular as BF3/COD and as popular as CS Was in it's day, there will be 1000s of new cheats made every day, and then constant changes to these cheats to keep them undetectable.
If BF3 didn't have PB, you would really notice the difference. Probably more cheating than not, much like CS1.1 days. I'm grateful for the job they do at PB, and tbh you should be too. I am also of the opinion that a lot of these "hackers" are anything but, and are just being accused of cheating because someone cannot understand how they killed them, so they "must be cheating."