INDEXED VIEWS WITH SCHEMABINDING
Why indexed views have to be defined with schemabinding ?
Got this answer from an MSDN Article. Its very nice.
So that all objects the view references are unanbigously identified
using schemaname.objectname regardless of which user is accessing the
view and the object referred to in the view definition cannot be altered
in a way that would make the view definition illegal / incorrect or
force SQL SERVER to recreate the index on the view.