Technically, yes, every personal computer is a PC. But that post is not wrong. It is widely understood that PC = Windows and Mac = Macintosh (now macOS). PC vs. Mac is a common term as well.
And let's not forget HP's misleading marketing slogan of: "HP, making the Computer Personal again" and yet another marketing lie as the only real option for this statement is GNU/Linux (without any code that prevents you from doing what you want with your system, true freedom). You also have to remember, historically computers were found mainly in workplaces, so when the general public had affordable access to computers, that I purport is when the term Personal Computer came into existence.
Yes, PC means Personal Computer. Unfortunately the overuse of this acronym to distinguish between Mac and Windows has settled in... hopefully it will be undone one day.
as far as I remember, bluestacks was for running Android apps, right?
On linux, we do that with another program: Waydroid
Unlike bluestacks on windows/mac, waydroid has way better performance because instead of running as a virtual machine, it runs in a different way that takes advantage of android technically being linux, so android apps run almost like native linux apps
If Waydroid is uncooperative (it's my understanding it doesn't like Nvidia at all) Genymotion may or may not meet your needs as an alternative. It's meant for enterprise Android developers, but there's a free license that retains most features and doesn't use your e-mail for marketing, since private use isn't their revenue source. It won't work with anything that needs Google Play services, but I'm able to run Arknights on it with perfectly good performance. If you try this route and need a hand, I'll write up steps. Arknights at least needs an ARM translation patch for Genymotion's virtual machine, and you have to modify the QEMU virtual storage, but none of it's hard, and it just takes a few commands from tools we can easily install with apt. Caveat: Genymotion is proprietary.
As for the PC thing, yeah. The IBM PC was the first to use that name, and as it and IBM compatible machines (once upon a time, you could buy boxed software that actually said "for IBM compatible PCs") first laid claim to the name, and Microsoft dominated that market, this is what we got. It's pretty much a historical thing by now.
I am so lazy, I usually say pc to mean any of my computers. Unless for some reason I need to denote form, then I say desktop or laptop. The only time I say Mac to mean one of my Macs is when the information is somehow relevant. For example in a Linux forum if I am talking about a distrubution that I run on what I would normally call my "laptop", I will often say "my mid-2013 MacBook Air" instead. I feel this is a public service, as other people that own the same model may one day search the web (as I did) to see if it was capable of running Linux. It is important to me to share this information because they will see they are able to run a modern and secure operating system on a machine that Apple no longer supports.
If it's any consolation, Bluestacks had gone way downhill even before I switched to Linux. They'd been great, got bought by now.gg, and became a nasty monetization/marketing mess.
I mentioned Genymotion above, too. If you don't mind telling me what you're trying to run/accomplish, I could see if it'll work with Genymotion, since I already have the setup done.
Going off topic was bound to be meaningful one day. I'll try On Stream in Genymotion in a few minutes, and look into Weston sometime this week. Genymotion works for some games, but it's a development tool and hit or miss for general use.
The site insists they're legit and legal, but this is absolutely, 100% unquestionably a low quality recording of a screen with terrible audio and blurry video. The fact that it's not available via the Google Play store, only via sideload, and that I got an OBVIOUSLY lascivious ad when starting a video to test strongly suggests this service is not legit at all.
I managed to get it to run under Xorg. I haven't really used it much, so I'm not sure if there are any limitations (beyond the resizing issue), but it does run: