Haha what I despise is singling out a particular tech corporation to hate as if they're an individual, but to each their own 🙂 There's this idea that AMD is somehow the 'little guy', despite still being a vast corporation with more power and money than most of us could ever dream of having. I'm a strong supporter of just buying whatever is best for the job (too bad there's often not a simple answer to that question).
It's interesting what you say about Far Cry 3 - Tom's performance benchmarking on it suggests it's extremely demanding (http://www.tomshardware.co.uk/far-cry-3-performance-benchmark,review-32584-6.html) but most people claim much higher framerates. I'm wondering if people are getting their own framerates from less demanding areas, or if a patch has made a big improvement. Maybe a bit of both.
It makes sense for Tom's etc to benchmark the most demanding areas to give a worse-case scenario of performance. I wouldn't want to buy something that looks capable based on best-case scenario performance to find that in the other half of the game it's laggy. I've seen this in a few games, Battlefield 3 for example. People claiming 60fps on hardware and settings Tom's got 30fps on. Worst-case scenario I think is always your safest bet though to be sure what you buy is capable.