Re: Too much choice
"Why does there ever need to be more than, say, 5 CPU models on the market, for any given generation?"
Well, there are at least that number of levels for power usage (very thin laptops 7-15 W, normal laptops 15-30 W, high-end laptops or compact desktops usually around 45 W, mid-range desktop parts often around 65 W, and workstations or gaming machines above 90 W). That's if I simplify quite a bit, because there's a lot of different levels in that "above 90" category, 15 and 28 produce very different laptop performance setups, and so on throughout the ranges. Having five units altogether would mean exactly one for each level. You want the AMD laptop processor, 6th gen? I hope you like it.
Even if we expand it to five per category, which is closer to what we actually have today, it's cost versus performance. If I'm going to buy a laptop for an office user, I don't want to give them a processor that'll produce awesome performance on complex games; in order to get that performance, it will cost double what the needed part costs and it will run down the battery faster unless they've markedly improved the firmware that scales down when the machine is idle. The packages we buy aren't even just a CPU. For example, you can have AMD processors with integrated graphics or without them. If you have GPU-intensive tasks so will be supplying a discrete graphics unit, skipping the lower-power included ones can allow you to get a cheaper or faster CPU-only device.
Comparison shopping between tons of models can be annoying, but there are benefits from not having to buy the top of the line because they didn't bother making anything else.