That's a great question, and I knew someone would ask it about both of those artists since they're both absent from my list and most definitely appear on tons of other 'top of the decade' lists.
The base answer is that I simply didn't listen to enough of their respective discographies to be able to add them to my list. These were all albums that I listened to all the way through, and frequently.
The longer answer is this; with Childish Gambino, it's just pure laziness that I haven't delved deeper into his stuff. As for Kanye, I've never been much for his music, so I really haven't liked his albums over the years. However, having said that, I have to also say that I really dislike the guy as a human being, which also makes me not want to listen to his work. I can't often separate the work from the artist if the artist is a garbage human being...and he's not someone I find myself respecting much, so I choose not to support his work or listen to it.
RE: My Top 50 Albums of the Last Decade