Apple isn't any different today than when Steve Jobs returned to the company. You are just mad that your computer doesn't have the hardware required to use AirPlay mirroring, which I really think is an overrated feature in ML, on the Xbox 360 and the Windows computers that also take advantage of this capability.
And in hardware you can't make everything in the past work with it, nor would you want to. Early HDTVs can't do BluRay, later BluRay TVs can't do 3D, etc. This is the life of technology. Current iPhones will not be able to do 4G LTE when an iPhone with that capability is released.
Apple is not cutting the life short on anything. I have an early MacPro. Can't run ML on it but it still capably does the same job for me that it did last week and the week before that. Planning on using it for a couple of more years then moving on. At that point it will be almost nine years old, pretty old for technology.
Apple has made their computers where they can't be fixed? They can fix all of their computers. But if you are referring to the rMBP, welcome to the future. I know you aren't near old enough to remember but you used to be able to work on your TV, take the suspected bad tubes to Ralph's supermarket, find the culprit, buy a replacement, put it in. Try working on any TV made in the past 10 years. Things change. How long do you think it will be before every other computer maker brings out their version of the rMBP? Months? Weeks?
If you are looking for eternal backwards compatibily you really should move back to Windows. But hurry before they release Windows 8. And if you are going to go the route of breaking licensing agreements go for it but I don't really care for people who do that, steal music, etc. and then proclaim themselves champions of the people.
As far as phones locked to carriers can you name any manufacturer in the US that has not done this. Apple tried a new cell phone paradigm with the original iPhone and was forced to abandon it and go to a more traditional contract with AT&T. They coudl not change the cell phone market in the US. And yes, if you legally unlock it (or bought an unlocked one from Apple, an option that has been around longer than AT&T, you can get it to work with supported carriers very easily all over the world. If you are using an unsupported carrier it is a bit harder because they do not include the necessary information on their microSIM for that hardware so you have to resort to manually entering the data. This is the same with all other cell phone manufacturers so you best bet there is to vote with your dollars and don't buy a cell phone.