The view update problem refers to the difficulty/impossibility of providing alternative updatable views on a database.
It's sometimes assumes views are associated with individual relvars.
It's more useful (and more general) to define a view as meaning a derived dbvar. Therefore a view means a set of named relvars. (just like the set of base relvars which are defined in the database schema).
It is assumed logical independence implies a view looks and behaves no differently than if the relvars in the view were declared as base relvars in a schema.
One of the purposes of normalisation is to avoid data redundancy and simpify updating the database. For that reason it is expected that an updatable view is normalised.