Nevermind, I finally found the solution in the SAP HANA Security Guide:
In order to be able to access an object with dependencies, both of the following conditions must be met:
● The user trying to access the object must have the relevant object privilege on the object as described above.
● The user who created the object must have the required privilege on all underlying objects and be authorized to grant this privilege to others.
We all had the select privilege on all the objects, but not as "grantable to others".
This means you cannot access the tables via view if the user who created this view is not allowed to grant the select privilege to you,
even though you might already own the select privilege on these tables!