I often wonder why web-startups need business co-founders. If you have an idea and can code it up yourself, what's stopping you? You certainly shouldn't wait around until someone else can go find money for you.
Ultimately I think the answer is, you don't have to have a co-founder. If you've got the gumption to go it solo, do it.
Startups are similar to musicians, there are solo acts as well as bands.