All the alt coins will also collapse with this. I do not think that we will ever see bitcoin coming to zero even if it collapses. People who were involved in the planning of this concept will remain invested with some amount just to support it. However, if it goes to $1000 or below (which can happen because of strict laws in developed countries), a lot of alt coins will be completely wiped out. We should keep in mind that most of these alt coins are sold based on the popularity of bitcoins only and thus they will suffer due to bitcoin prices decreasing.