I just spotted our current hnq question, and did a double-take before realizing what stack it was from. This happens more often here. Considering the recent mess with IPS, should we consider blacklisting, too?
For some added context, I also moderate Interpersonal Skills, the site that is currently on hiatus from the Hot Network Questions list.
Maybe . . . two or three years ago, I would have been a huge fan of this idea. At one point, we had a long series of discussions about what we termed "What If" questions (feel free to look back at all of those), which I think were being aggravated/encouraged by the Hot Network Questions list. The HNQ optimizes for controversy and open-ended questions in general, and while we have some pretty open-ended questions on the whole, we do have some limits. Looking back, I wonder if removing us from the HNQ would have helped mitigate the problem - and I still think so.
Part of my concern then was that we were still a fledgling site that had been through a whole bunch of trials and tribulations. My philosophy is that early access to the HNQ can harm a growing site that's still struggling to sort out scope problems and better manage its community. On Interpersonal Skills, we've known this is an issue for over a year now, which is why there was always some support to remove us from the HNQ. Now that it's finally happening, therefore, I'm fine with the change, since I view it as a necessary measure to protect the site from the network, and protect the network from the site. It goes both ways.
I think that at this point, Worldbuilding is strong enough to handle the outside traffic the HNQ brings. It's not harming us because we have a deep community that's basically kinda sorta wrangled a lot of the scope issues. Therefore, I don't feel that there's a huge impetus from our perspective to leave the HNQ. It has its plusses and minuses, but maybe no more for us than for some other sites (although we do get more questions on the list in general, so there's that).
So, then, there's still the main reason that IPS was removed from the list, namely, the effects on the rest of the network, especially the professional sites, as you point out. Monica suggests a pretty good fix that I've also been thinking about for the past few days: writing titles better, both to remove certain troubling words and to give more context to the question. I'm a big fan of this, and I'm working on ways to apply this to IPS. There are also, of course, other solutions to the problem which are being discussed on Meta Stack Exchange, but most of those are global, and will require us waiting on the rest of the network. Title-writing is something we can address ourselves and on a small-scale, case-by-case basis.
Finally, I do want to mention that I see the network drifting away from professional sites to include a large number of "hobbyist" communities. Worldbuilding is definitely one (for most people, although we do have some writers and game designers here, I believe), but even sites like Astronomy have an enormous enthusiast/amateur base. For me, the topic of that site is my career, hopefully, but it's supported by a strong community partly of enthusiasts. As the network continues to move in this direction, we're going to be forced to consider the possible shift in reasons for why a lot of people use Stack Exchange. That means that the perhaps less-serious/not professional/sorta-kinda-weird/less-tech-related/more-fun/distracting side of the network will be more visible, period. And with the rise of more Good Subjective sites on weird topics, hiding a lot of these non-traditional sites from the HNQ simply won't scale.
Sometimes a question that's perfectly fine in the context of a site looks alarming from outside. But that doesn't mean we need to opt out of external visibility. Sometimes an edit will fix that.
In this case, instead of "How can a person be kept alive while being periodically drained of blood?" (which raises questions of medical ethics and more, if you don't know where it's coming from), we could try something like "How can my golems keep people alive while periodically draining blood from them?". That exact title isn't 100% in accord with the question so I'm not making that edit, but maybe we can think of an edit that makes the question less alarming while still preserving its core.