Uh, guys...look through the material provided in the various links (including link to the other thread).
CAB wasn't put in effect because of what lay rescuers were doing. Pulse check was not eliminated. If anything lay rescuers for past few years have been doing better...by not messing around with A and B.
CAB was changed due to what WE (healthcare providers) were doing...taking too long from arrival to first chest compression. The A and B steps were delaying compressions (finding, assembling BVM, getting a good C-E grip) all the while this person was in cardiac arrest...in a situation where every minute/second to first compression counts.
If you only have 4-6 minutes before brain damage, even one minute from arrival to first compression is WAY too long.
Additionally, there's also the idea that if a patient does have depleted oxygen upon arrival, chances of him still having a shockable rhythm are very low...so this subset of patients have poor outcomes anyway. And for the ones who DO have oxygen remaining, at least we're circulating that right away and increasing survival chances for those who HAVE a chance. At least that's ONE of the thoughts behind it.
I'd love to have a protocol like the 200 compressions that some people posted about. That's shown incredible promise in several studies.