In Habitat sample project meta renderings and few similar sort of renderings have been used as dynamic rendering. Shouldn't such renderings be used as static rendering in layout? Is there any specific reasons/benefits to use these renderings as dynamic renderings. Thanks.
This is done in accordance with helix architectural principles. It states:
Avoid statically binding renderings in sub-layouts, but rather bind all renderings to layouts via layout definitions and placeholders. Static binding will make the page and solution structure less flexible and introduces multiple maintenance methodologies. Although you might end up with longer lists of renderings in your layout definitions, the centralised Page Type templates (see Template types) and single layout management methodology will prove more maintainable and flexible in the long run.