So I went round the five Adult infohubs - which, as far as I remember, were never in the Destination Guide anyway, so wouldn't be affected by the delisting.
Four of them are pretty much identical - the "Safe Hubs" at Arapaima, Nelsonia, Ungren and Vilania. The fifth is the River hub on the borders of the Oritz and Gilda sims; it is relentlessly modernist and has a nasty habit of dropping casual visitors into its water-filled basement on TPing in. Some things don't change.
The "Safe Hubs" have the same general regulations as any infohub (the Welcome Area Guidelines, somebody should probably read those someday.) So, you should be as safe at Ungren as you are at NCI Kuula from spambots, vampire attacks, gunfire and general griefer obnoxiousness. And, because the Welcome Area Guidelines are never enforced, you are. In half an hour, I was hit by spambots at Vilania, Arapaima (twice), Nelsonia and River, with a vampire attack at Nelsonia to boot. Safe Hub my aunt Jemima.
The thing is, the Adult hubs are populous, and that brings in nuisances. Now, I get the distinct feeling their popularity has grown over the time I've been in SL... and that sets me to thinking about why.
You might expect, just on random-traffic grounds, the Adult hubs to be busier; after all, there are only five of them, compared with more than twenty Moderate level hubs, so if the same number of people are being spread around the Adult hubs as around the Moderate ones, that means a greater concentration of population. (The populations of the hubs ranged from 15 to 25 people during my visits.)
Now, this, to me, implies that a lot of people - very possibly an increasing number of people, because I don't remember those Adult hubs being so busy when I started infohub touring - are choosing Adult content and setting their maximum maturity level rating to Adult. And I am moved to ask myself why.
The obvious answer is that SL is, as we all know, that weird online sex thing, and we are all cyber-perverts, and naturally we gravitate to those areas that allow most cyber-perversion. Obvious, but, in my opinion, wrong. It's my belief, actually, that rather less sex goes on in SL than in RL; a substantial number of people just don't "get" cybersex and SL sex, don't find it arousing, and hence don't go in for it. (It may be a substantial number, but I am not among it!) Even though there is also a substantial number availing themselves of SL's freedom to do things they wouldn't or couldn't do in RL, I think, on average, SL is less sex-crazy than RL by a notable margin.
But, the Adult areas are, well, Adult... and that doesn't just mean sex. Indeed, if you look on the login screen, you will see a number of - for example - "edgy" role-playing environments with Adult ratings; not because they are non-stop sex-fests, but because they are tackling material like horror, or graphic violence, or simply psychological themes that are best left to a mature audience. And that, I think, is at the core of the popularity of Adult areas in SL. (And they are popular - as I have found out, just looking at the comparatively buoyant Zindra land market.)
The key appeal of Adult areas, it seems to me, is that they are areas where you don't have to fret about the nature of your content; where it is assumed that everyone around is a responsible and mature adult who can make their own choices about what to do and what to view. This is, in some ways, what SL was in the old days, before the Teen Grid merger and what some people regard as the "Disneyfication" of SL. The Adult areas are, in short, places where you have full creative freedom, and you don't have to worry about people saying "but think of the children!" when you build your dark-RP community, or your challenging artwork... or, of course, your giant statues of dongs. Nobody says adults have to have good taste.
It's not unusual, too, in Adult areas, to come across adults actually acting like adults. Certainly, when someone is hitting on me in some sleazy sex sim (never mind why I'm in a sleazy sex sim in the first place), they respond to a rejection, as often as not, with a cheerful "OK", and move on to someone who might be interested. Or they stick around for conversation on general topics; I've had some surprisingly good times in sleazy sex sims, none of which actually involved sleazy sex. (Or, at least, none of them that I'm telling you about, because this is still Not That Sort Of Blog.) Compared with the horny adolescents who pursue inappropriate behaviours with relentless repetition across inappropriate venues like General-level welcome centres, your average naked Zindran cyber-perv is actually quite the gentleman. (Or lady. Or other.)
In short; there are legitimate reasons for seeing the Adult areas, not as sinkholes of depravity, but as places actual grown-ups can go to be grown-up in. And that is a good thing.