Because it is a Sony Link Removed. Dont you remember the huge problem when they took "other OS" out of the PS3 options? It is a way that some companies are trying to kill Linux. Microsoft isn't that bad, at least they are working with some Linux distributions.
Link Removed, it is correct to say that your computer is cost effective and works well. Though saying that it is up with the most current technologies is not correct. You have two open SATA ports, so that would come out to be four or six ports total. when most new boards come with between eight to eighteen. i3 processors are Hyper-threaded dual core processors, when newest models are running 4, 6, 8 and even 10 cores. On top of that they don't support Turbo Boost, Nice little feature to have, I have used it many times in the past. The new i3 is just another set in the long line of cheaper processors that are just a little bit behind the times. Also cookie cutter computer do not have parts that are designed to run perfectly together. They have parts that are designed to work together and have been proven. They can make check mark lists because they know what will 95.1% or higher allow the computer to turn on, past that, nothing in guaranteed.
Now after that, it has to be said that, if this computer is what you need and not overkill then that is what you needed to buy. One mistake people make is they don't buy what they need. A desk jokey needs little more than a dual maybe a quad core with four to six gigs of RAM and an on board graphics card. That is no where near the top of the line but, top of the line is not needed in that situation. That set up will serve him for years to come, thought I would say stay away from on board graphics. He may latter want to add multiple monitor support. So it is great that you found one that works for you. Just remember, it can always work better.