<snip>as for mission critical applications there are a bunch of macs running them. apple has decent penetration into legal markets where security is very important and a range of academic, business and medical applications where reliability is a bigger factor. ranging from single machines to massive clusters of xserves running OSX Server (iirc U Illinois has literally hundreds of em clustered up). Even the US navy uses xserve clusters ...<snip>
You were doing fine until you said this. I cannot count how many of the businesses, you listed, I have walked into and found their so called security to be a joke. Why do you thank banks continually lose customer information?
Companies use Windows servers because they believe the marketing Microsoft does. They also get used because many IT folks feel it secures a job for them. If there is a problem with the server, they can always blame Microsoft for the problem. Then there is the, "No one ever got fired for suggesting Microsoft products be used."
The only reason Apple is used by scholastic institutions is Apple gives the equipment to the schools. Apple donates more hardware to schools than any other company in the world. It is a good tax write-off.
The U.S. government procurement for computers takes years to get done. Apple is popular because they do not change their hardware often enough to have to continue to build obsolete equipment the government specified 3 years ago. I have been involved with that process. Many computer companies today will simply not participate in the government process for procurement of products.
At the end of the day, it is all about personal preference as a PC can do what a Mac can do and vice-versa. I can crash a Mac inside of 15 seconds. I can do the same to a PC. Apple's biggest plus is the fact they do not allow you to really do whatever you want with the computer. PC's are more open and easier to mess up as a result of that.
Apple computers are more of an appliance. You get what you get when you buy it. PC's are more for the tinkerer and as a result are more prone to have problems. Most of which, are user induced. Understand the limitations with either platform, make your choice, and be happy with it.