It's not a convention, it's generally best to access the field directly.

There is a `get_title` method on the `AbstractProduct`, but that is used as variant products use the title of their parent, so you can't use field access directly:
https://github.com/tangentlabs/django-oscar/blob/master/oscar/apps/catalogue/abstract_models.py#L522

I'll remove this method as we don't need it.