Genesis once bubbled...
that skill set in your OW class.
You don't, of course, which is a problem, unless you're conscientous enough to do it yourself.
Witness how many RENTAL reg sets (on which they train you) and how many purchased sets on dive boats that have $20 octos. You know the type - they MIGHT give you a gulp or two of air, MAYBE, they MIGHT have been serviced sometime in the last 10 years, and they MIGHT not be full of sand or mud when you need them.
In my experience diving on cattle boats, which I no longer do (but did when I started) I could count on the fingers of one hand the number of reg sets that had reasonably-identical performing primaries and backups. The shop that I took my training from had two different brands - one had "ok" backups, in that they were all SPs (and SP doesn't make a "horrible" reg) but the other were something else entirely. I had the "pleasantry" of using one for an S-drill with my dive buddy once and was damn near drowned due to rather extreme wet breathing (and in salt water too - yecch!)
Of the people on the cattle boats who owned their own gear, I think I saw perhaps two in all of my dives on them with good-performing backups. Most were the $50 kind, and even better, one guy who showed up without one (it was a requirement on the dive boat) had the crew screw on one of those "flat hockey puck" $50 ones on his kit so he could go diving that day.
Boy, that says a lot about how far beyond LIP SERVICE the folks paid to the ACTUAL requirement for a second air source, doesn't it?
THIS is the "state of the world" when it comes to training.
You want to rail against solo diving when this is reality in the so-called "buddy system" of diving generally? I was effectively diving solo during my OW class, because the buddy I was assigned was simply incapable of being one! What was my option? Refuse to dive with him? That's nice, then I don't get my cert at all, because now we suddenly have the "wrong" number of people in the class. And don't say "your instructor is your buddy", because you and I both know that my instructor is going to be doing something with other people most of the time, and of course Murphy doesn't pay any attention to when you might have an equipment problem.
I do not "condone" solo diving. I don't condone diving at all! Its an inherently hazardous undertaking in all of its forms, and the various combinations of diving and buddies (or lack thereof) is a matter for PERSONAL CHOICE.
My azz, my decision.
Period.