Mac users, consciously or unconsciously often mention the idea of the machine lasting, as if it's a rare thing for a PC laptop to last 5 years. Go ask people with higher end systems how old their notebooks are. My Sony is 8 years old, my mom's netbook is probably 5. The Asus I got today from a customer (needs a new drive) is 5 years old. I see LOTS of 5, 6 and 7 year old computers that have never been broken open. I even recently donated a 10 year old Sony to a local hackerspace, it still ran great. The problem is Mac people love comparing theirs to low end Acer, HP, etc... The number one thing that kills old pc's is the hard drive, same ones that are in Macs. So why don't people keep PC's as long? Because it's often almost as much to fix the PC as it is to buy another. When the drive in your $1500 Mac (still valued at $800) goes bad, you fix it. When the drive in your 2 year old $300 crapbox (worth $100) fails, you go buy another $300 crapbox. It's not that it's less reliable or less prone to damage, it's just more disposable, though one could argue newer Macs are becoming expensive disposables.
Macs look nice and while I love OSX from a design aspect, as a Windows and Linux user, it's infuriating. Dont' say it's because Windows, I've used everything from Apples 2's to DOS to BSD, BEOS, OS2, and more. Mac is easy to use, it's just the little things, like how Home and End work that throw me off and of course the single mouse button, which needs to die in the fiery pits of hell! Don't say "gestures", that's just a way for Apple to not have spend another 50 cents on a second button, how long before they ditch the remaining button, you have gestures that can make up for it right? It interferes with my flow while working.
I do get how some people like the idea that "it just works", it does, in the same manner as IOS does. So long as you never stray from the intended purpose, it works fantastic. The problems start as soon as you stray from the norm though, all hell breaks loose. As a power user, it just creates lots of issues for me and I never can seem to just leave well enough alone. When I did run OSX, I was always trying to tweak something to work how I wanted and being fought the entire way.
Another argument is how they look, one could argue that the Lenovo X1 Carbon has a great look, as does the Asus Bamboo notebooks, there was also the older Sony magnesiums (which could be polished to a mirror finish), the ultra light carbon fiber Sony laptops and recently the aluminum bodied Dell's (Adamo). Looking good is not a unique to the Mac, though you may need to pay Mac prices to get it. As for upgrades several of my laptops have had upgraded processors, memory, SSDs, wireless upgrades, converted the DVDs to an esata port or Blueray, added and removed 3g service, changed colors and looks, polished frames, and on my last Asus I was looking at upgrading the screen (which can be done on some systems). On some Lenovos you can even do more as they often go several generations with interchangeable parts. I've seen 6 year old Lenovo/IBMs get new boards and processors. You can't do half of that with a Mac and even less on newer ones.
That's because Macs are an appliance, like a dishwasher. It does a job, it does it well, just don't ask the dishwasher to do your laundry. If all you do is light work and surf, which Macs are great for, yes, it's great for that. But do you need a $1500 laptop to do it? Probably not, and there's the problem. Most people with a Mac, would do just as well on a low end Windows computer and replace it a little more often, which is exactly what most users who do that sort of thing do. The same happens with people using Iphones, I cannot tell you the number of people I run into who have top end Iphones who use it for Facebook and pictures. A $50 Android can do that.