QFT. Intel's shenanigans go back to at least Sandy Bridge. One chipset to rule them all? Nah. Oh wait, here's Z68, which should have been available at launch. But you still can't have VT-d if you also want to overclock, just because!
Z77 and Z75. No idea why Intel made Z75. The only difference was no smart response technology and no 3 way SLI.
Literally.
Not that I minded, as it saved me a few bucks. Maybe that's why we didn't see a two tiered Z series again that I recall.
The worst offenders have to be Skylake to present. Just look at the
buffoonery going on with CPU support. SK-L support KB-L, KB-L only supported KB-L, and CF-L only supports CF-L.
There was a time with AMD that on an nforce 570 SLI chipset I got the 3800+ X2, a die shrunk 5000+ X2, then a Phenom II X4 940. So one that board I got two die shrinks and went from 2 to 4 cores. I had to sacrifice some by using the old chipset, but it worked.
So when AMD went ahead and said socket AM4 until at least 2020, I was all over that. I have a feeling I will be on AM4 for another 3 years. Time will tell.