Friends won't always have the extremely honest and frank business conversations needed. I can give anecdotal evidence of this as I was lucky to work at a record

Friends won't always have the extremely honest and frank business conversations needed. I can give anecdotal evidence of this as I was lucky to work at a record label startup founded by friends. Both were 100% behind the company, but it took some 5 years to fully understand that 1 friend loved music (and saw the startup as a means to create the right environment for creative artists, viewing money as a side effect of that creativity) and the other loved money (and saw the startup as a means to create an environment in which to make money and viewed the creative process as a hindrance in the generation of product). It ended quite badly, the friendship was deeply affected by this and the signings reflected a pendulum shift from creativity to product creation. It has been argued that friendships will inhibit the asking of the kind of questions that would've rooted that out and in either scenario made it more successful, indeed that's my view of this one instance. So yes, friendship can be a real problem. Not that it's that black and white, friendships can also be a real boon as PG has mentioned it can be the difference that makes people stick with it through the harder times. So there's nothing conclusive either way. Depends on the people involved.