These are two well-known biases of YC. I believe the reasons are the following: * YC founders are usually very young, and young people can be capricious. They

These are two well-known biases of YC. I believe the reasons are the following: * YC founders are usually very young, and young people can be capricious. They don't want a solo founder just deciding to do something without a second founder having some leverage to protect YC. * YC is in the US and has a very pro-US perspective, so they invest in what they know and like.