There really is a great deal of tosh goes on in any thread that mentions MacOS or Windows!
They both do exactly the same thing just with a few differences in how.
There are advantages and disadvantages to both and I've listed them before.
I'm sat here typing this on a 2012 15" retina Macbook Pro Quad 2.6GHz (3.6Ghz) i7, 16Gb Ram, 512Gb SSD - It is the best laptop money can buy (other than paying silly extra money for the 2.7 (3.7) GHz or 768Gb SSD options of the same laptop). I bought it and will use it for an average of 2-4 hours a day for the next 4 years probably THEN I will sell it for maybe £600-800 and buy the next one. I have a 2008 Mac Pro - It still crunches anything I chuck at it so does not need upgrading (I treated it to a new graphics card this year) and runs a genuine server OS. I have a Windows machine running Windows 7 which is totally stable and built using the best components for the job, at the time (it's running one of the last Pentium 4s). I also have a proliant server running linux.
Most of the time most computers are waiting for the user to do something not the other way around and unless you are messing with rendering large amounts of video constantly you don't need anything quicker than last years machine anyway.
Raw speed is not the only thing that is important on a computer really is it. I run a browser, photoshop, a language compiler/linker/development system, electronic CAD software, programmable processor development systems, photoshop, illustrator, word, mail, indesign, multitrack music creation software and numerous other stuff without any problem...... but I didn't have any before I got this laptop and was using my previous one - 2008 17" Macbook Pro, 2.5GHz, 6Gb RAM, 512Gb hybrid SSD HD
Some people need to grow up. As a professional I buy what I need for the task. I use the OS that best suites me and the task. I use a laptop most of the time for portability so I get the best one there is.
Apple is popular at the moment because it is giving people what they want at the moment!
They have often charged a premium over the same Windows based kit BUT you often get this back when you sell it (my last MBP cost me £1600 after discounts and sold for £600 so £1000 for 4 years use works out at about £5 per week!). A 17" Windows machine would have been no quicker but would have cost about the same and sold for much less at the end. Also when you actually compare like for like in the laptop market Apple isn't often more expensive!! Yes you can buy a £300 laptop from Asda or Lidl but I wouldn't want one! I buy a quality machine because the contents and use are far more important than the machine but if you compare a quality Windows machine with a quality Apple machine the price isn't that much different.
Apple machines don't have it all their own way though. My Windows desktop has a 2006/7 motherboard but I have added USB3 and other things to it which is more difficult and expensive using Apple kit. I also use to like modding my computer and with Windows kit this is far easier. Adding an LCD panel, messing with cooling, over clocking etc etc
As for the malware debate .. There hasn't been a VIRUS out in the wild for MacOS but there have been a few very limited trojan attacks based on stolen software downloaded from torrent sites - You cannot really protect against this because when it installs it gets permission to change system files etc and the user gives that permission because they are installing some software. They don't realise that the software also contains malware but this is hardly a fault of the OS or Apple!.... Most "virus" attacks on Windows machines are nothing of the sort they are, again trojans or, other similar programs or quite often things like the hard drive filling up etc or people being fooled into installing programs they shouldn't etc. Windows XP and Windows 7 and very stable (some 3rd party drivers might not be)
Horse for courses.......
