That is actually very good and valid advice.
In the beginning its best to focus on quantity more. If someones focus is to improve its best to not get stuck and spend hours on details on a drawing. Drawing more things, focussing on the big shapes, learning proportions, perspective, shading etc.
(rule of thumb, 30 min for a simple drawing/subject or an hour for a bigger scene or something is the MOST you'd want to spend on a drawing at first.
Adding onto your advice: use lots of references and draw from there.
