A bit late to the thread, so this might have already been addressed, but... people complain about "bland" races, but some of the most unique and alien races are kenku and lizardfolk, and so many people hate what makes them alien because it makes them "hard to play." If kenku could speak and be creative, were as emotional as everyone else, they'd be just another anthro human with funny hats.
I love the narrative of Kenku. They imply a story akin to how Raven brought light to the world (and was burned for it). A similar story seems to exist in the Indo-European past given the meaning behind a lot of raven and crow words in European languages (association with burning, fire, char, soot, etc - there really seems to be an archetypal Icarian/Promethean idea behind many of the raven/crow stories of the world).
I also recognise that they're EXCEEDINGLY hard to play well, because you have to be ON when you're playing them. Some people just want to knock in the door, say "NOBODY TOSSES A DWARF" and get on with it. That's FINE.
Stereotypes are FINE in the game. The game runs on memetic energy. We need those memes for a laugh and to give our minds a break after a long week at work. If we're working too hard when playing, we might burn out.
But they SHOULD NOT be the be-all and end-all of character lineage & culture in the core assumed rules, lest the rules imply that the only correct way to play a Dwarf is bearded, male, with a double-headed axe and a Scottish accent.
So Kenku belong in the game too, but you're right, their difficulty in getting to work right in a game is a good warning against making the core assumed present lineages too complex that they become a chore to play. There's a reason why (Standard) Human Champion Fighter is so exceedingly popular: it's easy to pick up and play. There's no complex rules about it. Making that Human difficult to play would be contrary to the purposes of the core rules. Same deal with Elf, Dwarf, and Halfling, at the very least.
But WotC CAN and SHOULD open up the dials to let players tweak their lineages by faction or culture. And maybe, just maybe, culture would be a good replacement for the mechanical framework that lineage currently operates in. MAYBE. I'm not convinced, but it's a worthy discussion.