Yeah, I'm a bit surprised I got diamond, especially given that I'm actually trying to play legit ZvZs (well, like half the time, on Ulrena and any map with a wide natural I usually open 14g/15p) for the first time since early HotS and am generally clueless at it. The only explanation I can think of is that people are really bad.
Even though I've been diamond for like a year now I'm still pretty convinced that I'm not actually better, and Blizzard just tweaked the ladder to make it permanently easier. Though when
nios.kr says that GM+Masters+Diamond only comprises 12.5% of the NA ladder, man, it seems weird that in a dead game only the good players quit.