To be honest, mobile phones are the most abused consumer product out there. Making a manufacture adhere to a two-year warranty based on normal wear and tear seems too excessive. If that was the case, I would love the same protection for my car, when my tires wear out before two years, I want the manufacture to replace them. Going down this slippery slope will have repercussions not just in Apple land, but in every other mobile manufacture.
The other side is, Apple in the US tends to really take care of their customer, if your phone breaks due to a no-fault-error created by the customer, they replace it even if it is out of warranty. This is totally up to the store manager to make that decision however.
I also have to mention that AT&T has been very good to me as well by replacing my Samsung Note I numerous times with dying radio chips (7 times) and also totally replacing it with a Samsung S3 (3 times).
I now own a LG which I upgraded to and so far no problems.