Nah, many of our customers are baffled by this when they see it the first time too (and so was I when I first started playing with indexed views many moons ago) 🙂
For official reference (from https://technet.microsoft.com/en-us/library/ms181151(v=sql.105).aspx):
A query does not have to explicitly reference an indexed view in the FROM clause for the query optimizer to use the indexed view. If the query contains references to columns in the base tables that are also present in the indexed view, and the query optimizer estimates that using the indexed view provides the lowest cost access mechanism, the query optimizer chooses the indexed view, similar to the way it chooses base table indexes when they are not directly referenced in a query. The query optimizer may choose the view when it contains columns that are not referenced by the query, as long as the view offers the lowest cost option for covering one or more of the columns specified in the query.
Cheers!