First of all, there are pros and cons to practically everything. Both OSes have their advantages and disadvantages.
Windows is an operating system for most businesses. Many will agree that Windows has far more features geared towards remote management/deployment/etc. Office for Mac is basically a nuked version of Office for Windows. If you disagree, it's likely because you don't use the more advanced features. Microsoft is also more friendly towards business IT policies. There are other reasons for why Windows is better that I'm not going to mention as my goal is just to give an overall picture.
I feel that Mac OSX is somewhere in between Windows and Linux. It's an operating system that's based on Unix and thus, has certain advantages stemming from that background (look into this if you want, I'm not going to write an essay extolling the virtues of *nix). Because it's more popular than Linux, we see that it also has more programs available for general use. Obviously Linux still dominates it in terms of development tools. So if you want something for development and general work and don't want to use both Windows and Linux, then Mac OSX seems like a good option. Some people may not even need to use Linux for development, so Windows may work best for them. It all depends.
Personally, I've used Windows, Linux, and Mac OSX. I favor Windows for school/uni work because of some of the programs available for it (touch and pen-sensitive for writing/drawing diagrams is helpful as well). My peers with MacBooks end up carrying a MacBook and an iPad/tablet and syncing the two for their notes. Obviously my approach is simpler and more effective here, but it all depends on your situation. I also use Linux virtual machine(s) for testing and development. Yes, you could do it in OSX as well using Homebrew, Macports, etc.
As for Mac OSX, it usually sits unused, simply because I find that Windows or Linux does the job better. I haven't really found a case where OSX would have done the job better than one of those OSes, but I'm sure they exist.
Now, when it comes to laptops, I generally favor the ThinkPad and MacBook line due to their build. I've used both for an extensive amount of time and usually end up buying more ThinkPads, but that's usually because ThinkPads are undeniably more durable (some of the newer ThinkPads are a bit iffy in that regard). MacBook Pros with Retina obviously win in the screen battle. So it's really about what you value more.
In the end, people should choose technology that lets them get work done. I do believe that most people choosing OSX are doing it for the cool factor rather than anything else though. But that's my own personal experience and I can't back that up with statistics or anything.