Cannot Upgrade MacBook OSX 10.6 to 10.9

Question

I've looked through the forum, but haven't found a solid answer yet.
I went to upgrade my aging MacBook from Snow Leopard to Mavericks via the free upgrade available in the App Store. I got a message stating that my computer could not be upgraded.
I don't know what year my machine was made, but I don't understand why that would make a difference as long as the processing, memory and hard drive requirements are met. I have built and upgraded many Windows machines and the YEAR of manufacture of the motherboard or processor has never been a factor in upgrading to a newer operating system. Only the processor speed, amount of memory and hard drive space available would have any impact on the ability for an OS to perform correctly.
The only thing I can think of is that Apple, whether due to greed in forcing customers to purchase newer machines or other financial incentive, has placed such a limitation on the OS upgrade so that older machines cannot benefit from the new software technologies. I don't use this machine as part of my daily routine or for business, but I do like it for travelling due to its small size. It is also kind of a fun break from Windows and I like to keep up with other OS technologies such as OSX & Linux for my own self-edification and experience.
If there is some TRUE technical reason that the upgrade wont run on this machine and it isn't just financially or politically motivated by Apple, then could someone please explain to me (in technical, architectural detail) what the bottleneck happens to be? The year of manufacture and color of the casing just don't seem to be justifiable reasons to me based on my knowledge and experience (I have a Voodoo machine with a 10 year old mobo and processor that still outperforms several newer machines - although it is candy apple red!). Here are the specs of my MacBook as reported by "About this Mac":
Hardware Overview:
  Model Name: MacBook
  Model Identifier: MacBook2,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
  Total Number Of Cores: 2
  L2 Cache: 4 MB
Memory: 2 GB
  Bus Speed: 667 MHz
  Boot ROM Version: MB21.00A5.B07
  SMC Version (system): 1.17f0
Serial Number (system): W8*******YA9
Sudden Motion Sensor:
State: Enabled
I don't see anything in there that indicates the year of manufacture, but I'm thinking 2006 or so. It is black.
It runs Snow Leopard and Office 2008 just fine and, albeit quite sluggish upon initial load, Vista Ultimate via Parallels. If there truly is no way to get this machine running Mavericks, I'd like to hear some user suggestions for other ways to improve performance on this machine until it finally dies (which it shows no signs of - a little warping of the battery case cover is all that appears wrong with it). I've read that this machine will not take more than the current 2GB of RAM, but some have said upgrading the HD to a solid state drive would give it quite a kick (assuming this model and OS version would accept one). I'm also quite concerned about the fact that Apple is not supporting Snow Leopard anymore. Does that mean that there will not be security updates? Am I putting my machine and home network at risk by continuing to use this machine?
Any and all answers/suggestions are greatly appreciated. Thanks to those of you who took the time to read this and (objectively) respond.
-Domenick
Please note: If this post comes off as a little smug, it is not intentional – so please don’t yell at me! As a PC guy, I’m just having trouble understanding this one
<Edited by Host>

Answer 1

When or if you upgrade the MacBook 2.1 to a later OSX past Snow Leopard 10.6.8, it will lose the ability to utilize older (available, affordable?) applications that may be on it, which shared code with the older build series of OS X and the supported computer series using PowerPC processors, as these use a utility inside pre-OS X 10.7.x by the name Rosetta. This allows older powerPC coded application to run in later Intel-based Macs.
Once the computer is upgraded past Snow Leopard 10.6.8, Rosetta won't function; it won't be available since support for that ceased with continued System integration to intel-based hardware, to remove unneeded code.
So if you have older applications running, you can tell in System Profiler what ones may be incapable of running in Lion 10.7.5 since those willl say PPC in the applications section. Some may say Universal, others Intel or x86.
With an older early MacBook, it's probably best to leave it with a good solid system such as Snow Leopard 10.6.8, given enough quality RAM and adequate unused hard drive capacity for it to function well. Then be on the lookout for good examples of later hardware that will support more recent OS X versions and applications. Avoid auctions or ebay; if you know someone well enough to also know when they are talking bad about their old slower Mac and want to 'recycle' it, those are key words indicating you could do an intervention to save the poor old Macs life. Especially if it still runs, and looks unscathed. Acquire vintage hard + software while it is available, for the day you may want to be an iFixit guide practitioner? A few items are more difficult.
Good luck & happy computing!