If they're your family members, any stress from work comes home. There's no decompressing or escape, which can lead to conflict at work and home. If things go w

If they're your family members, any stress from work comes home. There's no decompressing or escape, which can lead to conflict at work and home. If things go wrong, you run the risk of blowing up both your professional career and home life. If they're other family members, same deal as you'll be caught in the crossfire. Meanwhile if things are going well, you'll still never have the same level of access to your cofounders as they have with each other.