I think that the investors may not just be looking to solidify infrustructure for other investments. The majority of start ups have little income and relatively few customers. Npm has a huge number of customers and whether it can generate a huge amount of income through private registries or whatever services, the fact that it is a core piece of infrastructure is a huge advantage in launching services. So a VC has good reason to expect a useful amount of income. That isn't actually the case for many investments. I don't see how anyone could suggest that this is a large investment for such a core piece of infrastructure.