See Levels of Action. Creating utopia is analogous to an object-level action, while avoiding extinction would be a meta-level action: avoiding extinction supports the creation of utopia (in fact it is, obviously, necessary). However, at some point, meta-level actions have to bottom out in an object-level action -- otherwise they were pointless.

See also Lost Purposes. If we devote too much of ourselves to avoiding extinction, our values may drift away and we may simply become survival-maximizing agents who never end up creating utopia.