> Customers never need to see each other's data. Correct and incorrect at the same time. Separate orgs may not need direct access to each others rows in the mu

> Customers never need to see each other's data. Correct and incorrect at the same time. Separate orgs may not need direct access to each others rows in the multi-tenant database, but there are plenty of use cases where data does need to be shared between them (companies with multiple orgs, like ours - business parters, etc) and Salesforce has tooling to handle this (Salesforce to Salesforce, Lightning Connect).