I feel like the comment was more directed on the kids' parents having to walk a mile in the Teacher's shoes. And the ease with which it is someone else's problem to make sure your kid learns.
There is certainly some of that. Being a teacher is certainly very difficult. However, theoretically at least, they are trained to be teachers, and it is their full time job, while for most parents it is not.
Additionally, being onsite at school there are fewer distractions, and just the environment of physically being on a school campus conveys that the primary focus of the day is education.
