By definition getting to the same results without co-founders requires a much higher level of ability
I don't think this is a compelling argument--investors don't care about your ability, they care about your company's results. If this is true, then co-founders are indeed a better bet.
Every screening mechanism is imperfect. Once everyone starts requiring co-founders, then there's a lot of value as an angel to being willing to consider single founders. But that doesn't mean investors who avoid single founders are wrong to worry.
I don't think this is a compelling argument--investors don't care about your ability, they care about your company's results. If this is true, then co-founders are indeed a better bet.
Every screening mechanism is imperfect. Once everyone starts requiring co-founders, then there's a lot of value as an angel to being willing to consider single founders. But that doesn't mean investors who avoid single founders are wrong to worry.