AMD really has nothing to offer me...
None of my favorite games use more than 4 cores. Most use 2-3. So Intel is ahead in that regard.
I care about the environment actually more than I care about gaming, so pretty much whoever makes the lowest wattage reasonably performing CPUs has my money. Intel is ahead there as well.
I keep my CPUs for at least 4-5 years (foolishly chose a Phenom II last time though), so that rules out heavy 24/7 overclocking, and pretty much defeats AMD's only advantage for me...
You could call me an Intel fanboy, I suppose. But that wouldn't really be accurate, considering fanboys seem to defend a company even in the areas it's weaker. And I would switch if Intel was actually weaker, because loyalty to a company that exists to make money is very silly.
To answer the question, AMD only has more cores because their cores share modules, and end up being much weaker. It's as much of a marketing ploy as anything, because a lot of standard users see "AMD 4Ghz 8 cores", and think it must be better than "Intel 3.5Ghz 4 cores", when in reality the opposite ends up being true. But it still gets AMD plenty of sales.
To be fair, AMD did do one thing exactly right; their gaming CPUs don't come with an iGPU. That's mostly where AMD's lower costs come from, because their APUs cost a lot more considering the performance. Intel could easily slash $50 off their prices without losing gaming performance if they cut out the iGPUs from some models of i5 or i7. (which they sort of did, with the Xeons)