I reckon the best summary I’ve heard was on a recent ATP. The Mac Pro when it was introduced, was pitched as “no long the CPU is the biggest thing - GPUs give WAY more power, and this machine is a GPU powerhouse”. Then they didn’t upgrade the GPUs for 3 years, and you can’t upgrade it yourself. Crazy.
There is more to computer upgrades than the CPU. SSD prices have fallen, but Apple is stuck on 128/256/512GB. GPUs have moved WAY on, but Apple is stuck with 3 year old units in Pro equipment. The Mac mini has less power than it used to, and no GPU option. DDR4 has been out for years, but Apple don’t use it.
The machines still work well, and are reasonably fast (as long as you don’t buy a non-ssd iMac!), but they could be better, and/or cheaper. Selling computers with 3-4 years old tech may be profitable, but it’s far more like the Apple of old. The golden era for Apple tech seems to have been just after the Intel switch. Suddenly the tech was comparable and they updated far more frequently…
Given how much better OS X is with a decent GPU, that’s the thing that bugs me the most.