Thats all good and fine for you. I have 2 MBP's; 1 is the last ppc version and the other is a 1st generation intel mbp. Unfortunatly for me the processor is a core2 and not a dualcore so I can only upgrade as far as Snow Leopard. Why is that? Oh because apple purposely didnt create Lion to be compatible with single core processors...because they want you to buy a new computer.
Now think about all those people that purchased a mac in 2006 or 2005 and paid GOOD money for it. They keep it updated to the point where it says its fully updated. Then these nice mac supporters go an buy an iPhone 5 or a iPad for $$$ and go home and plug it into their macbook and iTunes says that you need to update iTunes to version X. These nice people say okay, goto itunes website to download itunes and when they try to install it... They find out that the newest version of itunes is not supported on their hardware and now they need to spend $$$ to buy a new laptop. Bogus Dude.
Compared to the 3 or 4 laptops I have that are PC's -(2004, 2006, 2008, 2013) ranging from XP, VISTA, 7, 8... I can easily add some more memory (for cheap) and install Windows 8.1 on each of them. Oh and all versions of itunes work on them.
Review for a good laugh:http://mjryder.net/25-reasons-to-hate-macs-and-3-reasons-to-like-them/http://www.bluedamage.com/2014/05/19/why-macs-suck-part-3/