It’s just not fun gameplay.
There will be one when we do another cycle of monocolor Dragons. We do them about once a decade.
What’s the fastest turn-around? Three to four years, I think, and that’s with a very popular, deep mechanic.
We decided that not having a basic land type (and not being a basic land) was enough to make it not “strictly better”. I will admit, that this is us pushing this rule more than we have in the past. If this experiment doesn’t work, we might not push in this way again.
It was intentional, yes. We purposefully run mechanical themes through consecutive sets.
We shrunk the font beyond our normal limit.
All the humans are non anthropomorphic. : )
The planeswalkers serve as player analogues so it’s harder to move away from humanoids. We have a few, but they’re always going to be the exception.
Legendary creatures, in contrast, are a great place to do nonanthromorphic characters and we do a lot of them there.
Maybe. : )