There are two PhD physicists in this household. One is sitting across from me on the sofa: while she has a PhD in experimental astrophysics, she now works in radiation physics. On her lap is a Dell running Windows. Why Windows? Because as part of her job she needs to use quite a bit of specialized software (expensive commercial stuff), which is only available on Windows (not even on a Mac). The other physicist is sitting in my chair, and I currently have my office Mac on the lap. Sitting next to me is my 10-year old personal MacBook. If you claim that Macs are such total crap, how do you explain that this particular one has survived 10 years of heavy use (albeit with replacing the battery 3 or 4 times and the disk once)? The third computer sitting next to me is a used MacBook, vintage 2015, which I just inherited from my son (who went and got a brand-new MacBook, since he just went off to college); if I have an hour, I'll move from my 10-year old machine to the 3-year old one, but I haven't found the time for that yet.
By the way, I have lost track of how many Macs and iPads our son owns and uses. He used to also have a dedicated Windows machine for gaming; today, when he needs to run Windows games, he dual-boots his Mac hardware into Windows, using an external disk drive.
In the office, our group has about a dozen and a half PhDs, a mixture of physicists, mathematicians, statisticians, and computer scientists. Most have a MacBook as a laptop, while a few instead have a Chromebook. In theory it would be possible to also get a Linux- or Windows laptop, but I don't know anyone closely who has one. One of the fathers of BSD works in my office, and he has a Chromebook. The only people who have Linux laptops in my office that I know of are Linux kernel developers. Three of my colleagues have additional fixed desktop machines, and if I remember right, two are MacPro (the black cylindrical tower), and one is a Linux machine.
Because I have worked in research and physics for so long, I still know lots of active physicists. The vast majority have MacBooks as their go-around machine, a smaller number have Windows laptops. Among physicists who now work solely in computing, you find occasional Linux laptops. Yes, I have worked at CERN (somewhere on the web is a picture of me inside the CERN data center, with a few colleagues), and most people carry a Mac there. Found the picture:
http://www.lr.los-gatos.ca.us/2003/09/paul/DSCN0600.sml.jpg
Now, the machines where physicists do data analysis (and CERN has thousands of those in its data centers, and the big internet companies tend to have millions): Those nearly all run Linux. Remember, among supercomputers Linux has 100% market share (none of the publicly known supercomputers in the top 500 in the world runs any operating system other than Linux), and in compute servers (not web, database or business logic servers), the market share of Linux is also above 90%.
Dear puretone: I understand that you hate Apple and the Mac. That's your right. Other people hate spinach. But please do not make up facts that have nothing to do with reality, and are purely based on your emotions.