The reasoning provided by YC is in the subsequent tweet: "It's pretty rare for YC to fund solo founders, because startups take many years to get big and it's ve

The reasoning provided by YC is in the subsequent tweet: "It's pretty rare for YC to fund solo founders, because startups take many years to get big and it's very hard to stay motivated for that many years without a cofounder helping." YC has been reticent to fund solo founders since its inception.