People were picking up as many of the cheap exalted bros as they possibly could because you could have a 3/3-4/4 attacking guy super-early and just quickly win out the game when you played a guy with Evasion.wat
Exalted was good, but Bant certainly did not overpower the other shards.
The panorama lands fixed three colours. I mean, yeah, the odds of playing war monk or thoctar on turn three is unlikely, but turn four is not that uncommon. Then there's a mana creature at common that taps for three mana, while in KtK there's mystic at rare.
Unearth works with Devour. It wasn't uncommon to see them together in a deck, since a lot of playable unearth and devour cards were mono colour.
I won drafts with synergy in mind. For example, the U/B unearth deck with Corpse Connoisseur as the engine. Sometimes I didn't even need a third colour or it was a very light splash. Same with Naya (splash red or white) and Bant (splash white or blue). Basically, it's the same with KtK. Don't take cards of equal colour and expect to do well unless you pick nonbasics highly. The advantage of KtK is you can play a bunch of morphs, but in my experience you're going to lose if you can't unmorph them.
KtK, like every other set, has a bunch of unplayable commons and uncommons, a lot of them being enchantments, healing salves and lens of clarity. What's your point?
There's a very good reason why there are no mana critters at common/uncommon, they would be auto-1st picks in limited, much how Elvish Mystic was basically the best Green card in M15. This format is in large part about mana management/advantage and they would just be oppressive - the Raid BTE guy is really good too, but he doesn't let you have those same sorts of oppressively dumb starts.
People's draft decks/sealed pools are overflowing with playables in a way not seen since OG Ravnica block. The question isn't "do I have enough playables?" - it's "Which playables are best for my deck?" And a large part of the reason for doing that is of course the necessity of taking mana-fixing highly here. Because of that need, they bumped up the average power level of the rest of the cards. (Literally just realized this due to this conversation, lol.)