Shorten reckons, page-19

Yep, some parents aren't doing enough. Leaving it up to educators.

Anyway you were asking why the pollies are following a particular path.
So I Googled and I presume they are informed by these two recent reports.

Lifting our Game report commissioned by the States.
http://www.everyonebenefits.org.au/the_importance_of_early_learning_from_lifting_our_game_report

Through Growth to Achievement: Report of the Review to Achieve Educational Excellence in Australian Schools
https://docs.education.gov.au/node/50516