Sorry for coming to the party so late. I've missed a lot of opportunities to dance/comment and it is now too late to address certain points. However:
1. There is probably some real good reason that the agencies started off by teaching the buddy system and for continuing to do so. It may be that in the old days equipment was unreliable. Has that changed? For the number of divers who talk about carrying pony tanks, I'd guess that they don't think their equipment is reliable. Or, perhaps they don't trust their gas management skills. I'm going to guess that the implementation of the buddy system was in recognition of the safety margin it provided.
2. A buddy is like a piece of gear. If you forget to bring it on a dive, you may be able to borrow it from someone else. If that is the case, you must either overlook shortcomings in that piece of gear or sit out the dive.
3. I, like many others, enjoy having a companion on most of my dives. Yes, there are times that I like solitude, but I also like companionship. A buddy, even if an insta-buddy, provides that.
4. I have not yet read the article cited. However, my legal background gives me some insight on liability. A buddy is not a guarantor or insurer of the safety of the other buddy. Doctrines such as primary assumption of the risk will likely completely eliminate a buddy's duty of care relative to risks that are inherent in the activity, in appropriate jurisdictions. And, if there is no duty of care, there can be no liability for negligence. However, leaving defenses aside, a buddy's basic duty is to use reasonable care. Yet, from the posts I've read, it looks like many divers on this thread expressly decline not to use reasonable, or any, care. Just saying, "we are buddies in name only" or "we are just same-ocean divers" is an expression that one is going to exercise no care.
5. For those who are so fearful of being sued as a result of a dive accident, you might be better off with some other activity, perhaps chess. Or at least don't dive from a boat with other people.
6. Don't knock Australia over Watson serving time for being a bad buddy. He pled guilty to the charge and it looks to me like the judge had to take a position that facilitated that plea.
7. For non-professionals, in the event of a lawsuit, the liability coverage of most homeowners or renters insurance policies will likely cover it.